Mobility Friendly Design Standards:
A Framework for Delaware
DRAFT
February 2004
Prepared by
Institute for Public Administration
University of Delaware
For the
Transportation Management Association of Delaware
Delaware Department of Transportation
TABLE OF CONTENTS
Institute for Public Administration ..................................................................................... ii
Part I: Problem Statement and Definition of Mobility Friendly Design.......................1
Part II: National Perspectives and Best Practices ..........................................................8
A. Mobility Friendly Design .................................................................................8
B. Transit.............................................................................................................15
C. Traffic Calming ..............................................................................................20
D. Interconnectivity ............................................................................................23
E. School Transportation/Location .....................................................................26
F. Trails...............................................................................................................31
G. Effectiveness ..................................................................................................36
Part III: Delaware and New Castle County Activities .................................................43
A. Transportation and Land Use Policy ..............................................................43
B. Mobility Friendly Design ...............................................................................46
C. Transit.............................................................................................................57
D. Traffic Calming ..............................................................................................65
E. Interconnectivity.............................................................................................67
F. School Transportation/Location .....................................................................68
G. Trails...............................................................................................................71
H. Conclusion......................................................................................................72
Part IV: Appendices ........................................................................................................73
A. Works Cited: Delaware Sources.....................................................................74
B. Works Cited: National Sources ......................................................................76
C. Recommended Websites ................................................................................79
D. Recommended Books.....................................................................................80
E. State Strategies Map for New Castle County.................................................83
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
i
INSTITUTE FOR PUBLIC ADMINISTRATION
The following document was prepared by the Institute for Public Administration (IPA) in the
College of Human Services, Education and Public Policy at the University of Delaware. IPA is a
public service, education, and research center that links the resource capacities of the University
of Delaware with the complex public policy and management needs of governments and related
nonprofit and private organizations. IPA provides direct staff assistance, research, policy
analysis, training, and forums while contributing to the scholarly body of knowledge.
The summit associated with this document has been developed by the IPA in partnership with
the Delaware Department of Transportation and the Transportation Management Association of
Delaware with assistance from the Delaware Office of State Planning Coordination
IPA Director
Jerome R. Lewis, Ph.D.
Forum Partners
Roger Roy – Transportation Management Association of Delaware
Ralph Reeb – Delaware Department of Transportation
Constance Holland – Delaware Office of State Planning Coordination
Mobility Friendly Design Project Manager
Edward O’Donnell, AICP
Mobility Friendly Design Team
Robert Warren, Ph.D.
William Fasano, Research Assistant
Lorene J. Athey, ASLA
IPA Research, Review and Assistance
Lisa Brennan, Research Assistant
Erin Cole, Research Assistant
Mark Deshon
Nelcenia Downer
Bernard Dworsky
Ruth Fallis
Anna Hunter
Stephanie Infiesta, Undergraduate Assistant
Dená McClurkin, Research Assistant
Lisa Moreland
Camille Sawak, Undergraduate Assistant
Alexander Settles, AICP
Tai-Ju Rene Tseng, Research Assistant
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
ii
PART I.
PROBLEM STATEMENT AND DEFINITION OF MOBILITY
FRIENDLY DESIGN
Problem Statement
The transportation and travel characteristics of New Castle County continue to be molded and
influenced by the developing land use pattern. This pattern, comprised mainly of single-family
detached housing developments, creates limited opportunities for increased mobility. Mobility
includes various modes of travel, including auto, bus, commuter rail, walking, and bicycling.
Mobility also involves travel for various trip purposes such as employment, school, shopping,
recreation, and community services.
The challenge resulting from the developing land use pattern is how to design communities that
have proactive development standards for mobility friendly travel. In essence, best practice
integrates the design of transportation infrastructure with the land development process to
encourage people to travel by modes other than the automobile. Initially, mobility friendly
standards would be used in the design of new developments and applied where appropriate to
retrofit existing communities.
A significant part of the problem is educating and convincing future residents of the benefits of
living in a mobility friendly community. One benefit is that it increases access throughout the
community for a variety of trip purposes. In addition, the health benefits derived from increased
pedestrian or bicycling activity could be considerable.
As part of this study effort, existing state and county land development regulations have been
reviewed with the purpose of enhancing current mobility friendly standards. The standards will
be based on the needs of this particular county and will draw heavily upon national experiences
that have demonstrated successful application of mobility friendly design standards.
This document reviews the key mobility friendly concepts and recommendations developed
throughout the country. Part I discusses the concept of mobility friendly design and why it is
important. Part II reviews some of the national literature specifically related to six topics of
interest to Delaware: mobility friendly design, transit, traffic calming, interconnectivity, school
transportation and location, and trails. The review focuses on specific design recommendations
and the effectiveness of the recommendations where data is available. This section of the
document is not intended to be an exhaustive literature review, but is intended to summarize the
key topics, concepts and recommendations of national experts. Part III summarizes activities in
Delaware according to the same six topics. Policy documents, research, and recommendations
developed specifically for Delaware are reviewed in this document, as are implementation
activities by the state and New Castle County.
What Is Mobility Friendly Design?
Mobility friendly design describes a broad set of design solutions for maximizing the
opportunities of all people to move within and between communities independently and safely.
As a result, people with varied ability levels including children, the elderly, the disabled,
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
1
individuals with low income, and others, can move freely without facing barriers resulting from
transportation facilities and services.
Mobility friendly design encompasses many concepts including Transit-Oriented Design (TOD),
Traditional Neighborhood Design (TND), Neotraditional Design, New Urbanism, Sustainable
Design, and Smart Growth. Each of the phrases describes a general pattern of development
typified by a small town that includes a mix of land uses such as residential, commercial,
employment, schools, churches, parks and other government uses. The communities often have
sidewalks and street trees, with homes on relatively small lots. The street system is usually gridlike with lots of interconnecting streets and few dead-ends.
In the journal article Evolution of Personal Travel in Toronto Area and Policy Implications, Eric
E. Miller and Amer Shalaby define “sustainability” as meeting our current needs without
jeopardizing the needs of future generations. In addition, sustainability recognizes that short-run
gain must not come at the expense of long-run loss.
Two other concepts related to mobility friendly design include SafeScaping, and Universal
Design. In the book SafeScape: Creating Safer, More Livable Communities through Planning
and Design, Al Zelinka and Dean Brennan define “SafeScaping” as the design of public spaces
to promote perceptions of safety and reduce crime and the fear of crime. Universal design refers
to considerations for handicapped accessibility. According The Center for Universal Design’s
article What Is Universal Design, universal design began in the 1960s with demographic,
legislative, and social changes among older adults and people with disabilities. For example:
• Demographics: The average American lifespan is now 76 years. About 80 percent of our
population lives past age 65, and more than 40 million Americans will be over the age of
65 by 2010, with about eight million people over age 85 by 2020. In 1994, 20.6 percent
of Americans had some disability, and 9.9 percent had a severe disability.
• Federal Legislation: 1968 Architectural Barriers Act, 1973 Rehabilitation Act, 1975
Education for Handicapped Children Act, 1988 Fair Housing Act Amendments, 1996
Americans with Disabilities Act, 1996 Telecommunications Act. Each mandates
consideration of the needs of the disabled.
• Social: The quest for independence and equal rights has grown over the past century;
buyers of assistive technology now demand that products be designed with concern for
their impact on the image and function of the user; and aging members of the babyboomer generation have begun to see the usefulness of products conceived for people
with limitations.
Why Do We Want to Use Mobility Friendly Design?
We must broaden our definition of transportation to go beyond the personal automobile and
encompass other forms of travel, especially transit and walking. It is important to point out that
every trip has a pedestrian component, and therefore any actions we can take to improve the
pedestrian environment will improve mobility for everyone.
According to U.S. Census 2000 data, there are more than 500,000 people in New Castle County
among approximately 189,000 households. Of those residents, 21 percent were 14 years of age
or younger, and therefore not of driving age. Almost 20 percent (13.6 percent of the total
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
2
population) of residents older than 21 are reported to have a disability and may have difficulty
driving. An additional 15 percent were 65 years of age or older. This segment of the
populations may not be as likely to be in the workforce and possibly face limitations on their
driving. Four percent of the population of New Castle County does not speak English very well
and, as a result, may have problems driving. More than eight percent of the county’s population
lives below the poverty level and may not be able to afford a car.
Furthermore, of the county’s 189,000 households, almost nine percent do not have access to a
vehicle. Thirty-six percent of all New Castle County households have children under the age of
18. Almost ten percent of all households were single-parent families, and more than two percent
were households in which grandparents are raising children. Many of the census categories
overlap but, taken together, it is clear that many people in New Castle County would directly
benefit from easy access to non-automobile modes of travel.
Is Mobility Really So Unfriendly Right Now?
According to Michael Wallwork in Traffic Calming “How to Make Streets More Livable,”
provisions for pedestrians and mass transit were excluded from transportation planning and
design as the automobile became the dominant transportation mode in the 1940s. Cars became
more affordable, contributing to a mass exodus to the suburbs. Suburbs were segregated by
function into single-use zones, often by price. Cheap gas, low interest rates, the interstate
highway system and inexpensive land fueled suburban sprawl. As mass transit was removed, car
performance and road standards increased to facilitate high-speed vehicular travel. Sidewalks
and visual points of interest were eliminated, and open space was replaced with parking lots.
Due to the segregation of developments, a lack of roadway connections caused driving trips to
increase dramatically. Dead-end collector roads and single-entrance developments concentrated
traffic onto a few arterials with a high number of turning movements, leading to overload of the
arterial system and higher numbers of conflicts and crashes. The ensuing wide, high-speed roads
with multiple turn lanes divided communities and created barriers for pedestrians.
According to E. Miller and Shalaby, virtually all of the current urban trends in transportation
design and development are moving in the wrong direction such as increasing automobile
ownership, increasing individual trip rates, movement of population and employment into areas
less well-served by public transportation, increasingly complex travel patterns, and increasing
travel outside of peak periods. The combined result of the negative trends has been increased
auto dependency, congestion levels, environmental degradation, consumption of land, and
concerns for the long-term viability of existing transit systems. The status quo of unchecked
urban sprawl and ever-increasing levels of auto dependency is not only unsustainable in the long
run but is increasingly counter-productive in the short run. This is because the “solution” of
more roads/more cars/more sprawl is inevitably out-stripped by the additional congestion,
pollution, and other pathological impacts generated by roads, cars, and sprawl.
In 2003, Debbie Howlett reported in USA Today on a review by the Texas Transportation
Institute of 2001 federal highway data. The review finds the following:
• The average driver wasted 51 hours that year stuck in traffic, compared with 50 hours in
2000 and 47 hours in 1996.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
3
•
•
•
•
Highways were congested an average of seven hours a day, compared to 4.5 hours a day
in 1982.
The total cost of congestion was $69.5 billion in wasted time and gas, which amounts to
$520 per year for the average driver.
Easing congestion by providing more roadways would call for 2,875 miles of additional
freeway lanes and new roads.
Based on a 25-minute average commute, drivers in Washington, D.C., Maryland, and
Virginia spent 58 hours per year in traffic. In Baltimore, Maryland, drivers spent 47
hours per year, and in the Philadelphia, Pennsylvania-New Jersey area, 44 hours per year
in traffic.
In the article Impact of Transportation Infrastructure Development on Modal Choice, Mohsin J.
Sarker et al. conclude that capacity improvements to urban road infrastructure from the 1960s to
the 1980s created social, environmental, and [physical] problems in the 1990s and today.
Additionally, road investment has not kept pace with the growing rate of auto ownership and
traffic volume.
There are also health issues associated with this style of transportation and land use. As reported
by W.L. Roper et al. in Health and Smart Growth: Building Health, Promoting Active
Communities, there are many ways that our typical pattern of development discourages walking
including:
• Residential settlements
o Dependence on the automobile reduces the need and/or desire to walk.
o Residential developments are not connected to other residential, commercial,
office, religious or recreational facilities except by high-traffic roadways.
o Residential developments have wide roads, without sidewalks.
o Cul-de-sacs “reduce connectivity, increase distance to destinations and contribute
to heavier traffic on main roads.”
o Many developments lack proper lighting, narrow street widths, short blocks,
pedestrian-scale signage, public art and other aesthetic enhancements, wellmaintained sidewalks, shelter from the elements, benches, trees, and right-angle
intersections.
o Houses are set back from the street; few windows and porches facing the street
create a lack of “eyes on the street,” thereby reducing the feeling of safety.
o Density, perceived safety levels, the presence of sidewalks, and enjoyable scenery
can all impact physical activity.
o Schools are far away.
• Loss of Neighborhood Schools
o The trend is toward larger schools located on the edge of communities or “school
giantism.”
o It is no longer possible for many children to get to school on foot or bicycle.
o Greater portions of school budgets are being spent on transportation, taking away
from physical education curricula, intramural activities, recess, playground
construction, sports equipment and facilities, and the availability of after-school
sports and recreational activities.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
4
•
•
Lack of Recreational Opportunities
o Many new parks are under private land ownership, with fewer new public parks,
greenways, playgrounds and other recreational resources being developed.
o The elderly, the disabled, and individuals of low income are at a disadvantage –
“it limits the mobility and independence of people as they age and their physical
vigor and incomes begin to decline.”
Automobiles and Physical Safety
o “Unsafe roads impact health in two ways: they cause injuries and deaths due to
traffic accidents and they discourage people from attempting to use walking or
cycling as alternative modes of transportation – hence becoming a disincentive to
physical activity and contributing to more people in cars more often.”
o Wide streets with little interconnectivity and few traffic calming measures create
the conditions for excessive speed and danger for pedestrians.
Roper et al. also discuss the impacts of community design and growth patterns on public health,
including air quality, as a result of our automobile dependence:
• Mobile-source related air pollutants cause respiratory and cardiopulmonary problems,
headaches, and premature mortality.
• Exposure to particulate air pollution shortens human life and triggers asthma attacks and
respiratory irritations.
• Sprawl reduces physical activity and social interaction, which help maintain emotional
and mental health.
Finally, Karen Petersmark and Risa Wilkerson in the article Land Use Affects Public Health state
“Research has demonstrated that suburban residents drive twice as far, walk and cycle one-third
as often, consume twice as much energy and produce twice as much air pollution as their urban
counterparts who live where land use tends to be mixed.” Typical suburban forms of
development have been acknowledged to be land consumptive and bad for wildlife, water, and
air quality.
What Are Some of the Difficulties in Implementing Mobility Friendly Design?
E. Miller and Shalaby highlight a number of systemic obstacles to new development trends. For
example, as a society, we respect the rights of individuals to choose to live and travel where and
how they wish within the context of a market-based economy. It is also necessary to
accommodate continuing economic and demographic growth within our urban areas, which
inevitably involves new development on previously undeveloped lands. The authors point out
that the automotive and land development industries are central players in many urban
economies. Finally, current political structures emphasize maximization of local property tax
bases, resulting in “zero-sum games” being played as municipalities compete for employment
and population, often to the long-term detriment of the region as a whole.
In the brochure Connecting Transportation & Land Use Planning Street Connectivity
(Community Planning Workshop), a number of barriers to integrating land use and transportation
planning are highlighted including:
• Political mistrust/disagreement.
• Lack of transportation financing for all modes of transportation.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
5
•
•
•
•
•
•
•
•
Public perception and lack of wanting to change.
Regulations that do not allow the principles to be implemented on the ground.
Built infrastructure that promotes more development.
General bias towards automobiles.
Lack of funding for long range planning.
Ordinances that do not allow smart growth strategies.
Difficulty educating citizens about the benefits of smart growth.
Resistance by developers to trying new ways of development.
Additionally, Genevieve Giuliano, in the article Land Use Policy and Transportation: Why We
Won’t Get There from Here, identifies policy trends that have contributed to this issue, including:
tax and pricing policies favorable to car ownership and use; the Federal Interstate Highway
construction program and the Highway Trust Fund; federal tax and mortgage policies that
support home ownership and favor suburban residential development; and political
fragmentation and powerful local governments that allow suburbanites to escape urban social
and fiscal problems. In theory, the policies supported deeper social and cultural values,
including the tradition of strong private property rights, historical preferences for single-family
home ownership, the suburban ideal, and ethnic and racial conflicts.
Other trends such as the shift to a service- and information-based economy and improvements in
information and telecommunications technology have made firms and individuals more
“footloose.” Service industries require less fixed infrastructure than manufacturing, and so are
more easily relocated. Large-scale population suburbanization has been followed by large-scale
employment decentralization. Commuting between suburban locations is now responsible for
the major traffic flow in the United States.
Changing individual decision-making will be difficult as well. Giuliano further points out that:
• The United States continues to have the highest car ownership rate in the world.
• Decreases in non-motorized trips suggest substitution of longer trips for short trips, as
well as population shifts out of core city areas to less dense (and therefore fewer bike- or
pedestrian-accessible) areas.
• The major explanatory factors in mode shifts are rising affluence, changing demographics
and household structure (decrease in household size and the increase in non-family
households), changing labor-force demographics, changing land patterns, and the
increasing value of time.
• As demand for housing increases, households are willing to travel more in exchange for
preferred housing characteristics, neighborhoods, etc.
• Shopping has become a leisure activity and people are less willing to patronize the closest
shops and more willing to travel farther to obtain greater variety, better quality, etc.
According to John Miller and Lester Hoel in The “smart growth” debate: best practices for
urban transportation planning article, the most direct causes of inefficient suburbanization
patterns are increased incomes, decentralization of employment locations, and automobile usage.
Additionally, studies suggest that development patterns will be slow to change, probably
remaining fixed for at least the next 20 years.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
6
Sarker et al. note that modal share studies have shown a clear and steady shift from public and
non-motorized transport to private automobile.
It is clear that there are many benefits to adopting mobility friendly land use and transportation
design standards. It is clear, also, that the standards have not been fully embraced by the policy
makers or the public at large for many reasons. Part II of this document reviews national best
practices with respect to mobility friendly design divided according to the six topics of interest to
Delaware: mobility friendly design, transit, traffic calming, interconnectivity, schools, and trails.
The section will also discuss the limited research regarding the effectiveness of the best
practices.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
7
PART II.
NATIONAL PERSPECTIVES AND BEST PRACTICES
As noted in part one, mobility friendly design encompasses design solutions related to the full
range of transportation options and addresses the individual abilities of the traveling population.
For this paper, a number of subtopics have been broken out and will be treated separately
including transit, traffic calming, interconnectivity, schools and trails. The last section will
discuss research regarding the effectiveness of the best practices.
A. Mobility Friendly Design
This section will address best practices related to universal design, traditional neighborhood
design/smart growth techniques and perceptions of crime and safety.
Universal Design
Universal design refers to design that accommodates people of all abilities, enhancing their
safety, independence, and dignity. With the passage of the Americans with Disabilities Act
(ADA) in 1996, all new buildings and public-works projects are required to be handicappedaccessible. The law, however, did not require immediate retrofit of the existing transportation
system, only compliance as improvements were made. As a result, many places still are not
handicapped-accessible. With respect to transportation and mobility friendly design, the law
primarily affects pedestrian and transit service and facilities, such as sidewalks, street crossings,
buses and bus stops.
The seven principles of universal design, according to the article What Is Universal Design?
(The Center for Universal Design), include:
• Equitable Use: design is useful and marketable to people with diverse abilities.
o Provides the same means of use for all users and avoids segregating any users.
o Gives provisions for privacy and safety.
o Appeals to users of all abilities.
• Flexibility in Use: design accommodates a wide range of individual preferences and
abilities.
o Provides choice in methods of use.
o Facilitates the user’s accuracy and precision.
o Provides adaptability to the user’s pace.
• Simple and Intuitive Use: design is easy to understand, regardless of the user’s
experience, knowledge, language skills, or current concentration level.
o Is consistent with user expectations and intuition and eliminates unnecessary
complexity.
o Accommodates a wide range of literacy and language skills.
o Arranges information consistent with its importance.
o Provides effective prompting and feedback during and after task completion.
• Perceptible Information: design effectively communicates necessary information to the
user, regardless of ambient conditions or the user’s sensory abilities.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
8
•
•
•
o Uses different modes (pictorial, verbal, tactile) for redundant presentation of
essential information.
o Maximizes legibility of essential information and provides adequate contrast
between essential information and its surroundings.
Tolerance for Error: design minimizes hazards and the adverse consequences of
accidental or unintended actions.
o Arranges elements to minimize hazards and errors; most used elements should be
the most accessible; hazardous elements must be eliminated, isolated, or shielded.
o Provides warnings of hazards and errors and provides fail-safe features.
Low Physical Effort: design can be used efficiently and comfortably and with a
minimum of fatigue.
o Allows user to maintain a neutral body position.
o Uses reasonable operating forces and minimizes sustained physical effort.
o Minimizes repetitive actions.
Size and Space for Approach and Use: provides appropriate size and space for approach,
reach, manipulation, and use, regardless of user’s body size, posture, or mobility.
o Provides a clear line of sight to important elements for any seated or standing
user.
o Makes reach to all components comfortable to any seated or standing user.
o Accommodates variations in hand and grip size.
o Provides adequate space for the use of assistive devices or personal assistance.
Although these principles have been developed to address people with disabilities, following
them makes mobility easier for many people without disabilities, including children, the elderly,
parents of small children, and people carrying bulky or heavy items. While ADA requires
facilities to be designed to certain standards and dimensions, additional attention to the needs of
the disabled beyond the requirements enhances mobility for all users.
Julie B. Kirschbaum et al. provide standards for designing accessible sidewalks and trails in
Designing Sidewalks and Trails for Access Part II of II: Best Practices Design Guide. The
sidewalk corridor is divided into a number of zones with suggested minimum standards such as
the following:
• Curb zone is immediately adjacent to roadway.
• Planter/furniture zone is the area between the curb and the pedestrian zone.
o Many cities with on-street parking allow for 36 inches.
o Locations with transit stops may require additional space (a boarding pad is
typically 60 X 96 inches), wheelchair lifts may extend to 48 inches beyond the
side of the vehicle, and a bus shelter may require a 96- X 156-inch space.
o Areas with snow may need additional space: minimum recommended width of 72
inches to allow for clearing.
o Furniture, where it can be placed on adjacent property (such as residential lawns),
should have recommended minimum width of 24 inches (not eliminated
completely).
o Extra space is needed at pedestrian crossings between the curb and the pedestrian
zone for two perpendicular curb ramps.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
9
•
•
Pedestrian zone is the area of the sidewalk corridor specifically reserved for pedestrian
travel.
o Commercial and urban areas may require larger pedestrian zones based on the
anticipated number of users, according to the Highway Capacity Manual.
o Paths or sidewalks less than 60 inches wide should have periodic passing spaces
of at least 60 X 60 inches no greater than 200 feet apart.
o Pedestrian zone should never be less than 36 inches wide for accessibility reasons.
o Obstacles should be eliminated in the pedestrian zone, including mailboxes,
telephone poles, and water fountains, which decrease the clear width of the
sidewalk and make walks inaccessible for the disabled.
Frontage zone is the area between the pedestrian zone and the property line.
o Zone should be a minimum of 12 inches.
o Zone can be eliminated if it is adjacent to a wide-open or landscaped area (lawns).
o Individuals who are visually impaired use this zone for orientation from building
noise and tend to travel between 12 and 48 inches away from the buildings.
Table 1: Sidewalk Corridor Minimum Dimensions
Zone
Minimum Width
Curb Zone
6 inches
Planter/Furniture Zone
24 inches (48 inches for trees)
Pedestrian Zone
60 inches
Frontage Zone*
30 inches
Total Sidewalk Corridor
10 feet
*If 2.5 feet of open space is available between the sidewalk corridor and the property line no frontage
zone is needed, the minimum resulting sidewalk corridor width is 7.5 feet.
Sidewalk maintenance is another important component of accessibility. Frequent problems
include step separation (vertical displacement 0.5 inches or greater on any point in a walkway);
badly cracked concrete (holes and rough spots wider than 0.5 inches); spalled areas (fragments
from building materials from larger structures); settled areas that trap water (segments with
depressions, reverse cross slopes, indentations); tree root damage (cause the walkway surface to
buckle and crack); vegetation overgrowth (ground cover, trees, or shrubs that have not been
pruned); and obstacles (objects that obstruct passage including trash receptacles, utility poles,
newspaper vending machines, and mailboxes). Responsibility for maintenance may belong to
the local government, homeowners, or businesses. Regardless of maintenance responsibility,
local government inspectors should review and approve all repairs. In addition, signs, signals,
and other information should be reviewed periodically for usefulness, degradation, etc. All signs
should be in compliance with the Manual on Traffic Control Devices (MUTCD) and ADA
Accessibility Guidelines (ADAAG). Lastly, citizens should have access to a convenient means
to report problems with timely responses.
Gary O. Robinette’s book Barrier-free Exterior Design: anyone can go anywhere included a
number of recommendations that focus on providing a barrier-free environment for people with
physical disabilities of all kinds, including:
• Vehicular traffic should be separated as much as possible from bicycle traffic and both
should be separated from pedestrians.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
10
•
•
•
•
•
•
•
Paving surfaces should be hard and relatively smooth; curbs should have ramped cuts;
and walks should be sufficiently wide to accommodate two-way traffic (five-feet-sixinches minimum; six feet preferred). Utility poles, newspaper boxes, signage, hydrants,
etc. must not be allowed to infringe on the clear width of the walkway.
Drop-off zones should be located as close to building entrances as possible, with no grade
change [curb] between the roadway and sidewalk. Waiting area with lighting and
protection from weather should be provided.
Sidewalks throughout a site should provide a clear, direct route through the site. Rest
areas should be provided adjacent to the sidewalk (but not infringing on the clear width
of the walkway) where pedestrians must walk long distances or up slopes.
Sidewalk maintenance is imperative to eliminate any conditions that may cause injury.
Drainage structures should be avoided within sidewalks, but when they occur, they
should be placed flush with the surface in which they occur. Do not use grates with
narrow parallel bard or grates with openings larger than 3/4-inch. Never locate a grate
between a curb ramp and the corner of the street, or immediately downgrade from a curb
ramp. Always locate drains perpendicular to the direction of vehicular and pedestrian
traffic.
Mid-block crossings should be used in pedestrian areas where block lengths are long.
Intersections and crossings should be designed with clearly marked crosswalks,
pedestrian signals with buzzers, and traffic islands with pass-throughs, at all legs of the
intersection.
Some additional technical recommendations (above and beyond ADA) were developed by the
Public Rights-of-Way Access Advisory Committee of the U.S. Access Board. The guidelines
for well-designed new sidewalks, documented in Building a True Community: Final Report,
include:
• Sidewalks shall contain a pedestrian access route and reduced vibration zone. The
minimum clear width for the reduced vibration zone shall be 48 inches.
• Pedestrian access routes should have a minimum clear width of 60 inches. The clear
width of the pedestrian access route may be reduced to 48 inches at driveways and alley
crossings, constrained building entrances, and at street fixtures.
• Pedestrian access routes should have a maximum cross slope of 1:48.
• Grades shall be consistent with the adjacent roadway.
• Stairs shall not be a part of the pedestrian access route.
• Visual contrast, where present, is required at the leading edges of stairways.
• Vertical and horizontal separation of the sidewalk from the street is encouraged.
• Provision of driver alerts at exits to parking structures is encouraged, and research is
recommended.
• Wall-mounted and post-mounted objects in the pedestrian access route are discouraged.
• Street identification signs shall meet readability criteria.
Smart Growth Techniques
Many researchers, organizations and designers have weighed in on the discussion regarding best
community design practices.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
11
Michael Southworth, in the article Walkable Suburbs? An Evaluation of Neotraditional
Communities at the Urban Edge, describes neotraditional design as characterized by higher
densities, a greater mix of land uses, provision of public transit, accommodation of the pedestrian
and bicyclist, and an interconnected street pattern.
The Metropolitan Council article Creating Livable Streets: Street Design Guidelines for 2040
provides the Portland metropolitan area with regional street design guidelines to support the
goals of the Metro 2040 Growth Concept and the Regional Transportation Plan. The council
sought to create a pattern of mobility that uses the car in the most effective and least harmful
manner, and “to promote community livability by balancing all modes of transportation.” The
council recommends in the article that community and transportation design:
• Provide travel mode choice.
• Support regional multi-modal travel.
• Support the economic vitality of the region.
• Create pedestrian and bicycle accessibility.
• Support public social contact.
• Provide orientation and identity to the region.
• Provide a safe environment.
• Provide for physical comfort.
• Provide spatial definition by orienting buildings to the street.
• Provide high quality of construction and design.
• Maintain the quality of the environment.
In 1994, Prevention magazine published Blueprint for a Walkable Community: Florida’s 12Step Program, which made the following recommendations:
• Step 1: Provide Continuously Linked Walkways. All walkways should connect in one
seamless path leading wherever one would like to go. Ideally, walkways should have
shade trees, plantings, benches, transit-stop shelters, and directions to places of interest.
• Step 2: “Pedestrianize” intersections. Use design features that cause cars to slow down
when turning. Use design elements that reduce the amount of time a walker spends
crossing traffic. Channel intersections so that a pedestrian only has to cross two lanes of
traffic at a time.
• Step 3: Design for Americans with Disabilities. Install corner ramps and raised
crosswalks to facilitate mobility. Design and standardize signals to be more accessible
and help the visually impaired.
• Step 4: Place Signals Properly. Place signals for optimum visibility for both pedestrians
and drivers. Be careful not to place signals too high.
• Step 5: Illuminate. All intersections should be well lighted, including the crosswalks and
waiting areas.
• Step 6: Simplify Median Crossings. Build landscaped medians into existing roads to
allow pedestrians to cross wide roadways more securely. Focus on high-volume
pedestrian areas around schools, entertainment areas, malls, and residential
neighborhoods.
• Step 7: Make Walking to Schools Safer. Identify specific places for buses and cars to
drop off children, away from pedestrian areas. Designate areas for children to cross
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
12
•
•
•
•
•
streets safely with as little vehicular contact as possible. Design all roadways around
schools to automatically slow traffic.
Step 8: Eliminate Backing Up. Design parking areas with walkways for pedestrians,
eliminating the need for walkers to be behind any car that may be backing up.
Step 9: Make Stores More Accessible. Parking areas should be adjacent to or behind
stores instead of serving as large barriers that walkers must cross. Create streets in front
of stores that have attractive pedestrian areas with benches and convenient crosswalks.
Design mall parking lots with networks of shady pathways that lead to storefronts.
Commercial areas should have sidewalks and pathways leading to and from nearby
neighborhoods.
Step 10: Create Auto-restricted Zones. Restrict vehicles to specific spaces and/or times
in busy commercial activity centers.
Step 11: Combine Walking with Transit. Planning and zoning should encourage
development that enhances transit use and access.
Step 12: Plan Walking into New Developments. Development and redevelopment
should favor walking over driving.
The Metropolitan Council, Robert Cervero in Transit-Supportive Development in the United
States: Experiences and Prospects, and Reid Ewing in Pedestrian- and Transit-Friendly
Design: A Primer for Smart Growth emphasize the importance of enhancing personal safety as
an essential component of mobility friendly design. Zelinka and Brennan, in the book
SafeScape: Creating Safer, More Livable Communities through Planning and Design, articulate
a number of design principles to ensure safe public spaces. Most of the principles are directly
applicable to mobility friendly design, especially with respect to pedestrians.
The first principle is Information and Orientation. To feel safe, people want to know where they
are and how to get to their destinations safely and efficiently, irrespective of their modes of
travel.
• Street signage and neighborhood identification should be provided, where appropriate.
• Signs should clearly articulate rules, warnings, and directions.
The second principle is Stewardship and Ownership/Management and Maintenance. When an
area has a neighborhood identity and is well maintained, people feel safe. Travelers perceive
that the residents care about the neighborhood and are monitoring the area. Conversely, graffiti,
trash, and general disrepair are signs that nobody cares or is watching.
• Clear boundaries/borders enhance public spaces (e.g., pedestrian cut-throughs) define
ownership, and encourage appropriate behavior. The boundaries/borders, however, must
be carefully designed and maintained for visibility and optimum sightlines.
• Use landscaping to create interest and individuality, and to establish boundaries.
Landscaping must be carefully designed and maintained so as not to obstruct walkways,
visibility and sightlines.
• Maintain sidewalks, buildings, streetscapes, neighborhoods, and districts to maximize
perceptions of safety.
• Maintain lighting fixtures in good working condition.
• Restore or demolish abandoned and neglected buildings and properties.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
13
•
Encourage development of vacant and infill parcels. Often the parcels contribute to
neighborhood decline and provide a place for undesirable activity. Interim uses can
include pocket parks and community gardens.
The third principle is Community, Site and Building Design. This can be designed to provide
“eyes on the street,” which enhances safety because criminals do not want to be seen.
• Design neighborhoods that blend single- and multi-family housing, to allow for a more
diverse population [such as retirees, stay-at-home moms, residents who work alternate
shifts, home-based businesses, and students]. Diverse populations have less-identifiable
behavioral routines; therefore it is more likely that someone will be at home and watching
at any given time of the day.
• Reduce/remove barriers between adjacent land uses. Barriers can be created by walls,
fences, berms, landscaping, buildings and other means. Provide a designated pedestrian
connection through the barrier.
• Separate pedestrian and vehicular movement. This is especially an issue in parking lots,
and where entrances and driveways cross sidewalks.
• Design for slower traffic speeds to increase pedestrian comfort. Additionally, high-speed
traffic provides fewer “eyes on the street” and greater ease of escape for criminals.
• Design for maximum visibility with windows, etc. where alleys are used.
• Provide informal gathering places such as community gardens and parks, plazas, and
seating at building entrances.
• Locate parks, playgrounds, and sidewalks where visible from neighboring buildings
and/or the street.
• Design walls and fences to be short or transparent to allow for observation of enclosed
public spaces.
• Provide light for evening use and shade during the summer through sidewalks and
pedestrian ways.
• Avoid pedestrian tunnels and bridges as much as possible. When necessary, they should
be as short as possible, straight, wide (wider than the adjoining path) and well lighted.
Bridges should allow for full visibility from within and without.
• Do not allow blank walls to be located adjacent to pedestrian areas such as siting areas,
sidewalks and parking lots. Walls should be articulated with windows, murals and other
architectural detailing to create visibility or the illusion of visibility.
• Set back garages away from the street. Doors, windows and other activity areas (porches,
patios, etc.) should face the streets.
Finally, J.R. Stone, M.D. Foster, and C.E. Johnson note in the article Neotraditional
neighborhoods: A solution to traffic congestion? that neotraditional planning is a topic of debate
and disagreement within the planning community. At this time, a great deal of experimentation is
taking place in the United States. Florida has 15 neotraditional communities on the drawing
board. Projects to retrofit existing neighborhoods in conformance with traditionalist precepts
have been proposed in Bellingham, Washington; Stuart, Florida; and projects in California,
Texas, Alaska, Virginia, Maryland, North Carolina, and Georgia.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
14
B. Transit
The following section addresses community and site design best practices that are recognized as
supporting transit usage, often called Transit-Oriented Development or a Transit Overlay District
(TOD). The concepts advocate that land around transit stations should be used in such a way as
to encourage transit system ridership, by making transit and other non-automobile modes of
travel more attractive and easier to use. This type of development has also been promoted to
enhance the use of existing urban resources and infrastructure, and reduce the need for
development of greenfields.
Existing TODs tend to be one of the following types:
• Redevelopment around urban transit stations, generally to create a mixed-use
neighborhood.
• Development around suburban transit stations to create a mixed-use neighborhood,
and/or services and parking to support the transit station.
• Redevelopment of an existing suburban town center.
• New greenfield development.
According to Wallwork, most areas developed prior to World War II evolved as naturally transitfriendly, due to the fact that transit, predominantly the street car, was the primary form of
transportation at that time.
In the article Transit Oriented Development: Using Public Transit to Create More Accessible
and Livable Neighborhoods, the Victoria Transport Policy Institute describes the general
characteristics of TODs as places where residential and commercial areas are designed to
maximize access to transit and non-motorized transportation and encourage transit ridership with
other features. TOD is characterized by a center with a rail or bus station, high central density,
and pedestrian-scale distances. TOD incorporates several specific design elements, including a
focus on cycling and walking, traffic calming, mixed-use development, and parking
management. TOD can consist of new suburban neighborhoods designed around public transit
stations, or incremental changes to existing urban neighborhoods with public transit service.
The Victoria Transport Policy Institute lists some TOD best practices:
• Integrate transit and land use planning.
• Provide high-quality pedestrian and cycling facilities around train stations and bus stops,
based on universal design.
• Manage parking to minimize the amount of land devoted to car parks around stops and
stations.
• Encourage car sharing to reduce the need to own automobiles.
• Create complete communities, with shops, schools, and other services within convenient
walking distances of transit.
• Structure property taxes, development fees, and utility rates to reflect the lower public
service costs of clustered, infill development.
Peter Calthorpe, in the book The Next American Metropolis, summarized the principles of
transit-oriented design as:
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
15
•
•
•
•
•
•
•
Growth throughout the region that is organized to be compact and transit supportive.
Commercial, housing, jobs, parks and civic uses that are within walking distance of
transit stops.
Street networks that are pedestrian-friendly and directly connect local destinations.
Housing types, densities, and costs that are intermixed.
Preservation of sensitive habitat and high-quality open space.
Public spaces that are the focus of building orientation and neighborhood activity.
Infill and redevelopment encouraged along transit corridors within existing
neighborhoods.
In Transit-Supportive Development in the United States: Experiences and Prospects (Cervero),
the key elements of transit supportive design are organized into three categories: land use, site
design, and pedestrian/transit facilities. The elements are:
• Land use includes encouraging a mix of land uses, providing transit-supportive densities
[at least seven dwelling units per acre (du/acre) or 50-60 employees per acre where total
employment is at least 10,000 employees], locating the highest density development
closest to the transit stop, locating new development along transit routes in existing
activity centers, and focusing new development within a quarter- to half-mile of the
transit stop.
• Site-design elements include locating retail and office buildings close to the roadway,
minimizing the distance between the transit stop and the building entrance, discouraging
abundant free parking, connecting neighborhoods and transit stops with direct pedestrian
walkways, configuring streets to allow for through and efficient movement of transit
buses, and linking adjacent development parcels with new roadways.
• Pedestrian and transit facilities include using road geometrics to allow transit,
appropriately locating transit stops, providing landscaped, paved walkways with safe
street crossings [including through parking lots], providing bicycle-friendly facilities,
ensuring that all buildings, walkways and transit facilities are ADA accessible, and
designing for pedestrian safety and security.
In 1997, Reid Ewing developed a checklist of 23 pedestrian- and transit-friendly features,
divided into Essential, Highly Desirable, and Nice Additional Features. In Pedestrian- and
Transit-Friendly Design: A Primer for Smart Growth, Ewing notes that all transit users are also
pedestrians, therefore pedestrian-friendly design is also transit-friendly design.
The essential features for pedestrian- and transit-friendly design include:
• Medium to high land use densities: high densities can comfortably be achieved by small
buildings with high lot coverages (50 to 70 percent). Pedestrians are uncomfortable in
areas with high-rise buildings with low lot coverages, surrounded by acres of parking and
lawn. Strive for at least seven du/acre residential, and/or a minimum of 50 employees per
acre.
• Mix of land uses.
• Short to medium block lengths: more intersections mean more places where cars must
stop and pedestrians can safely cross. Short blocks and frequent cross streets create the
potential for more direct routing for pedestrians and vehicles. A dense network of streets
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
16
•
•
•
•
•
•
•
disperses traffic so each street carries less traffic. As a result, streets are easier for
pedestrians to cross and can be scaled back in size accordingly. Three-hundred-foot
blocks are ideal, but 400 to 500 feet are still acceptable. Any block larger than 500 feet
in length needs mid-block crosswalks and pass-throughs for pedestrians.
Transit routes every half-mile, if transit stops are closely spaced along routes and local
streets lead directly to the stops. If stops are infrequent or local streets are curvilinear,
parallel routes must be even closer together.
Two or four lane streets (with rare exceptions).
Continuous sidewalks wide enough for couples: A five-foot sidewalk is wide enough for
two people to walk comfortably abreast, where pedestrian traffic is light, street furniture
is limited and buildings are set back from the sidewalk. Wider sidewalks are warranted
when the conditions are not met. At peak times, sidewalks must provide at least 25 sq ft
per pedestrian, 40 sq ft is better, but 100 to 150 sq ft is ideal.
Safe crossings: Marked and lighted crosswalks. Accident rates are significantly lower
where marked crosswalks are provided and crossings are lighted. Richard Untermann
recommends marked crosswalks every 100 feet on streets with heavy pedestrian activity.
Mid-block crosswalks slow down traffic in the immediate vicinity and discourage
pedestrians from crossing between parked cars. Design street corners to be sharp (fiveto ten-foot radius) rather than rounded, and flare sidewalks at the corners to create
neckdowns.
Appropriate buffering from traffic provided by greenstrips between the walk and the
curb, and street trees.
Street-oriented buildings: Buildings should be set back no farther than 25 feet from the
street and ideally be flush with the sidewalk or set back just far enough to allow for
landscaping. Locate surface parking to the side or rear –never allow parking more than a
row or two deep in front. Main building entries must face the street, and significant
numbers of windows need to be at street level.
Comfortable and safe places to wait.
Highly desirable features for pedestrian- and transit-friendly design include:
• Supportive commercial uses such as coffee shops, news stands, dry cleaners, child care,
and food stores.
• Grid-like street networks.
• Traffic calming along access routes.
• Closely spaced shade trees along access routes: trees at the right spacing in the right
locations contribute to many pedestrian-friendly design objectives including comfort,
safety, human scale, linkage, visual enclosure, complexity, coherence and a sense of
place. Shade trees should be placed close enough together to form a continuous canopy
over the sidewalk (30 feet or less on center). Locate trees between the street and
sidewalk to form a physical and psychological buffer.
• Dead space and visible parking eliminated or minimized: avoid blank walls. Parking
spaces have become the principal source of dead space in cities. Nine percent is said to
be the upper limit on the amount of land area devoted to parking; beyond that people
sense that the environment is no longer theirs but belongs to cars. Studies have shown
that downtown pedestrian counts in small cities fall as the amount of open parking
increases. Some suggestions: set parking maximums, give credit for on-street parking,
Mobility Friendly Design Standards: A Framework for Delaware
17
DRAFT: February 2004
•
•
•
make use of shared parking to reduce parking requirements, substitute parking garages
for surface lots, and build satellite parking facilities to free pedestrian streets from heavy
parking demands. Parking should be screened with attractive walls, hedges or berms.
Parks and other public spaces, which serve as attractions for pedestrians and add
character to the street environment, should be provided. Well-connected plazas generate
a substantial amount of impulse use; sunken or elevated (less visible) plazas do not.
Small-scale buildings (or articulated larger ones).
Upscale transit facilities.
Nice Additional Features for pedestrian- and transit-friendly design include:
• Street walls encouraged through the use of build-to lines instead of the typical minimum
setbacks.
• Functional street furniture, including benches, lighting, and trash receptacles at regular
intervals.
• Coherent, small-scale signage: If designed and applied thoughtfully, signs can add
several pedestrian-friendly qualities to streetscapes such as human scale, complexity,
coherence, and sense of place. Signs within an area should have a consistent vocabulary
of heights, sizes, shapes, materials, colors, and lettering. Signs should be sized based on
the design speed of the street upon which they front.
• Special pavement can contribute human scale, linkage, complexity, and coherence to the
streetscape. Bricks, cobbles, precast pavers, and patterned concrete, however, cannot
compensate for otherwise poorly designed street space. It has less visual impact than
large, closely spaced street trees. Special paving can reinforce and enhance other
transportation objectives such as traffic calming. It can visually break up large paved
areas, provide linkage between buildings, streets and public spaces, and clearly delineate
pedestrian, bicycle, and vehicular rights-of-way.
• Loveable objects, especially public art can increase pedestrian activity. Focal points can
help define spaces and bring character to the streetscape.
In addition to the recommendations for pedestrian safety outlined earlier in this report, many of
Zelinka and Brennan’s recommendations are also applicable to enhancing transit system safety.
• Locate bus stops where visible from neighboring buildings/land uses and the street.
Lighting is very important at all transit stops.
• Locate bus stops adjacent to businesses and other community activities to benefit from
additional lighting and visibility.
• Avoid placing bus stops near liquor stores, bars, gun stores, adult-oriented uses and other
undesirable uses. Chaperone uses such as police stations and fire houses can neutralize
potentially negative uses.
• Design bus stops and shelters for customer comfort and safety: good visibility both from
within and without, route and schedule information, shelter from weather, and seating
and lighting.
• Design landscaping to improve comfort, create interest and individuality, and establish
boundaries around transit stops. However, it must not obstruct walkways, visibility, or
sightlines.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
18
•
•
•
•
Maintain sidewalks, shelters, and seating to maximize perceptions of safety. Graffiti,
trash, and general disrepair are signs that nobody is watching or cares.
Maintain lighting fixtures near bus stops in good working condition.
Provide schedules and other route information at all bus stops.
Clearly articulate rules and directions for transit usage.
Several places where transit-oriented design has been put into practice are mentioned in the
article Transit Oriented Development: Using Public Transit to Create More Accessible and
Livable Neighborhoods (Victoria Transport Policy Institute), including Maplewood, New Jersey
(www.stationfoundation.org), Portland, Oregon (TOD Zoning Code), and Arlington County,
Virginia.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
19
C. Traffic Calming
In addition to promoting motorist safety, the reduction of traffic volume or speed improves the
quality of life in residential areas and other parts of the community, as a result of increased
pedestrian and bicycle safety.
According to Traffic Calming “How to Make Streets More Livable” (Wallwork), the average
household generates about ten vehicle trips per day. In a neighborhood with 1,000 households,
this amounts to 10,000 trips per day, often channeled onto only one street/entrance. Unwittingly,
communities have created the need for traffic calming by mandating wide roads, long straight
streets, and cul-de-sacs, while at the same time banishing schools, neighborhood stores, and
parks from neighborhoods. Emergency services requirements such as fire-truck access often
dictate the design width and curvature of streets. In reality, the majority of residential
emergency calls require an ambulance that is able to easily negotiate streets designed for the
average automobile. Wider streets have been found to encourage higher vehicular speeds.
The best way to avoid residential traffic conflicts is to design residential neighborhoods that
reduce vehicular speed and the need for vehicular trips. To achieve that result, a combination of
mixed-use development, fine-grained street networks, and short streets, combined with T- and
four-way intersections controlled by traffic calming devices is recommended. In addition, traffic
calming devices are being used at selected mid-block locations, and street pavements are being
narrowed to 10-, 16- and 24-foot widths.
Traffic calming involves retrofitting physical devices onto street networks to reduce vehicular
speeds, eliminate cut-through traffic patterns, and create a more pleasant street environment for
residents and pedestrians. Other benefits include reductions in air pollution, noise, and odors.
Traffic control devices are designed and located to keep through traffic on arterial roads and to
control the behavior of the remaining motorists.
Physical devices include retrofitting streets with slow points, speed humps and speed bumps,
chicanes, and roundabouts, which physically force motorists to slow down. For new
construction, streets can be narrowed, brick paving used instead of asphalt, and special street
designs incorporated.
To be effective, a traffic calming program requires a structured planning process, community
participation, and consultation with all relevant authorities. Traffic calming schemes work best
when there is a consensus of residents, with a 65- to 75-percent approval rate adequate to ensure
acceptance. An area-wide or neighborhood approach is necessary to avoid shifting the problem
from one street to another.
Wallwork recommends, also, that subdivision standards and road design manuals be changed to
require multiple entrances to distribute traffic volumes; narrow streets; permit on-street parking;
limit the length of streets to less than one-quarter mile, unless other traffic calming devices are
built-in; add sidewalks to both sides of the streets; separate sidewalks from the curb by a six-foot
nature strip; add trees on both sides in the nature strips; use small corner radii; and add schools,
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
20
corner stores, and parks to neighborhoods within walking distance, thereby reducing vehicular
trips.
In Traffic Calming: State of the Practice, Reid Ewing and the Institute of Transportation
Engineers (ITE) define traffic calming as the combination of mainly physical measures that
reduce the negative effects of motor vehicle use, alter driver behavior, and improve conditions
for non-motorized street users. It is intended to be self-enforcing and rely on the laws of physics
rather than human psychology to slow down traffic. There are a wide range of physical
measures outlined in this manual. The purpose of volume control measures is to discourage or
eliminate through traffic. Volume control measures include:
• Full Street Closures – barriers placed across a street to close the street completely to
through traffic, usually leaving only sidewalks or bicycle paths open.
• Half Closures – barriers that block travel in one direction for a short distance on
otherwise two-way streets.
• Diagonal Diverters – barriers placed diagonally across an intersection, block through
movement and force cars into side streets.
• Median Barriers – raised islands located along the centerline of a street and continuing
through an intersection so as to block through movement at a cross street.
• Forced Turn Islands – raised islands that block certain movements on approaches to an
intersection.
The primary purpose of speed control measures is to slow traffic. Speed control measures are
divided into vertical, horizontal, and narrowing measures. Vertical measures use forces of
vertical acceleration to discourage speeding and include:
• Speed Humps – rounded, raised areas placed across the road.
• Speed Tables – essentially flat-topped speed humps often constructed with brick or other
textured materials on the flat section.
• Raised Intersections – flat, raised areas covering entire intersections, with ramps on all
approaches and often with brick or other textured materials on the flat section.
• Textured Pavements – roadway surfaces paved with brick, concrete pavers, stamped
asphalt, or other surface materials that produce constant small changes in vertical
alignment.
Horizontal measures use forces of lateral acceleration to discourage speeding and include:
• Traffic Circles – raised islands, placed in intersections, around which traffic circulates.
• Roundabouts – used on higher-volume streets to allocate rights-of-way among competing
movements.
• Chicanes – curb extensions that alternate from one side of the street to the other, forming
S-shaped curves.
• Lateral Shifts – curb extensions on otherwise straight streets that cause travel lanes to
bend one way and then bend back the other way to the original direction of travel.
• Realigned Intersections – changes in alignment that convert T-intersections with straight
approaches into curving streets that meet at right angles.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
21
Narrowings use a psycho-perceptive sense of enclosure to discourage speeding and include:
• Neckdowns – curb extensions at intersections that reduce roadway width curb-to-curb.
• Center Island Narrowings – raised islands located along the centerline of a street that
narrow the travel lanes at that location.
• Chokers – curb extensions at mid-block that narrow a street by widening the sidewalk or
planting strip.
Table 2: Names of Traffic Calming Measures
Name in Report
Also known as
Full street closures
Half closures
Diagonal diverters
Cul-de-sacs
Partial closures
Full diverters
Median barriers
Forced turn islands
Speed humps
Speed tables
Median diverters
Forced turn
channelizations
Road humps
Trapezoidal humps
Raised intersections
Raised junctions
Traffic circles
Chicanes
Lateral shifts
Realigned
intersections
Neckdowns
Intersection islands
Deviations
Axial shifts
Modified intersections
Center island
narrowings
Chokers
Dead-ends
One-way closures
Diagonal road
closures
Island diverters
Pork chops
Undulations
Speed platforms
Right turn
islands
Raised
crosswalks
Plateaus
Raised
crossings
Serpentines
Staggerings
Reversing curves
Jogs
Twists
Nubs
Bulbouts
Knuckles
Intersections
narrowings
Mid-block medians
Median slow points
Median chokers
Pinch points
Mid-block
narrowings
Mid-block yield
points
Intersections
humps
Constrictions
Traffic calming measures can be effective at reducing speed, volumes, and collisions. Not all
traffic calming techniques are appropriate to all roadways. They are considered most applicable
to local residential or subdivision streets. Some highly urban pedestrian streets, however, may
be appropriate candidates for traffic calming.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
22
D. Interconnectivity
The Connecting Transportation & Land Use Planning, Street Connectivity brochure
(Community Planning Workshop) states, “Connectivity implies a system of streets with multiple
routes and connections serving the same origins and destinations; it relates not only to the
number of intersections along a segment of a street, but also to how an entire area is connected
by the street system.” The brochure describes the characteristics of a highly connected area as:
• A dense system of a parallel routes and cross-connections within an area, typically
forming a grid-like pattern of arterial, collector, and local streets.
• Few closed-end streets such as cul-de-sacs, dead-end, and looped streets.
• Many points of access.
• Narrow streets with sidewalks or off-street paths.
• Frequent intersections to create a pedestrian-scale block pattern.
• Traffic calming devices such as curb extensions, crosswalks, and landscaping to slow
traffic speeds.
• Pedestrian and bicycle connections where street connections are not possible due to
barriers. Physical barriers may include topography, freeways, railroads, pre-existing
development, lease provisions, easements, covenants, or water features.
Benefits of interconnectivity as described by the brochure include:
• Provides drivers, walkers, and bikers with multiple direct routes for traveling short
distances while preventing them from being forced onto arterial roads. This provides
better opportunities for walking and bicycling to local destinations such as shops,
schools, and friends’ houses.
• Shortens travel distances, making travel more direct, reducing travel time, increasing
accessibility, and lowering the number of vehicle miles traveled.
• Reduces traffic volumes on arterials and better accommodates long-distance travel.
Local traffic stays local and is accommodated by a network of smaller roads.
• Better accommodates the development of town centers with short blocks (typically 200 to
400 feet in length) in interconnected street patterns compared with typical strip
developments found along arterial roads with long blocks.
• Better accommodates transit use because transit stops are more accessible from
neighborhoods.
• Lowers speeds on local streets, resulting in reduced accident severity.
• Increases access by emergency vehicles and improves response time.
Recommendations for achieving connectivity as described by the brochure include:
• Space street connections no more than 530 feet apart, except where prevented by barriers.
• Make provisions for bike and pedestrian accessways no more than 330 feet apart when
full street connections are not possible.
• Limit the use of closed-end streets to situations where barriers exist.
• Design closed-end streets so that none may be longer than 200 feet or have more than 25
dwelling units.
• Use narrow street design alternatives.
• Make public right-of-way routes short and direct.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
23
•
•
Consider opportunities to incrementally extend streets from nearby areas.
Consider the use of traffic calming devices.
Kent Butler, Susan Handy, and Robert Patterson describe some of the arguments for and against
street connectivity in the book Planning for Street Connectivity. The arguments include:
• Positives include a decrease of traffic on arterial streets; more continuous and direct
routes that encourage travel by walking and bicycling; greater access and quicker
response times for emergency vehicles; more evacuation alternatives in the event of a
disaster; and improvements in the quality of utility connections, facilitating maintenance
and enabling more efficient trash and recycling collection and other transport-based
community services.
• Negatives include increased levels of through traffic on residential streets; increased
infrastructure costs and impervious cover; requirements for more land to develop the
same number of housing units; decreased affordability of housing; and perceived
decreased profitability of developments.
The report offers research results and studies based on the experience of 14 communities’ efforts
to incorporate greater connectivity, including Raleigh, North Carolina, and Austin, Texas,
making the following recommendations:
•
Regulating Connectivity: The block length requirement used by most communities so far
has been easy to understand and simple to implement, since it generally requires only a
change to existing block length requirements in the local code. The connectivity index
allows greater flexibility in the design of street networks and serves as a performance
standard in the development-approval process. However, these are not the only possible
approaches and not necessarily the best. The fundamental goals of connectivity
requirements are to increase the numbers of connections and the directness of routes.
More direct measures of the goals include the number of intersections per mile of road
(the converse of block length) and the ratio between network and straight-line distances.
•
How Much Connectivity: The differentiation of streets based on movement versus access
functions is essential for both accommodating and “taming the car.” It is possible,
however, that this differentiation has gone far beyond what is necessary to achieve its
purpose. The key for communities is to find an appropriate balance between minimizing
traffic on residential streets and dispersing traffic throughout the network.
•
Network Design: Most of the communities studied allow curved streets, and nearly all
allow cul-de-sacs in certain situations. Those using a connectivity index requirement
offer the greatest degree of flexibility in the design of the street network, since they focus
on a network’s performance rather than its shape. An examination of traditional
neighborhoods built before World War II, which are all well connected, often reveals
greater discontinuities than one might expect. Correspondingly, the street networks in
most new developments labeled New Urbanist do not follow a perfect grid. Connectivity
measures can help to create a new type of network if they shift the focus from the
structure of the network to its performance.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
24
•
Non-Automobile Modes: In general, improving connectivity for cars should improve
connectivity for bicycles and pedestrians, unless streets are poorly designed. If separate
facilities are provided, bicycle and pedestrian connectivity can be even greater than car
connectivity. Transit connectivity can benefit, also, from improved connectivity in all
modes, although the amount of improvement depends on the design of transit routes. By
influencing the travel distances for each mode, connectivity requirements can have an
important impact on mode choice. Davis, California, well-known as a bicycling
community, encourages high levels of pedestrian and bicycle connectivity through a
system of greenbelts, but allows wide use of cul-de-sacs that tend to lower automobile
connectivity.
•
Commercial Areas: In response to traffic congestion, some communities have made
efforts to ensure connectivity between commercial sites. In San Antonio, Texas, the city
negotiates shared driveway arrangements with developers, a practice that helps keep the
number of driveways along frontage roads within the limits set by the Texas Department
of Transportation.
•
Existing Street Networks: Finding a way to retrofit existing developments may be the
most contentious issue of all. Infill developments and redevelopment projects can be
used to increase local connectivity, but the overall effect is usually insignificant or, at
best, marginal. Efforts to add bicycle and pedestrian paths to existing residential
developments can generate considerable resistance from nearby residents.
In Does Increased Street Connectivity Improve the Operation of Regional Streets? Case Studies
from the Portland Metro Regional Street Design Study, James Daisa, Tom Kloster, and Richard
Ledbetter conclude that an interconnected street system improves traffic flow on arterial streets.
Higher levels of interconnectivity can be achieved through smaller block sizes, elimination of
cul-de-sacs, elimination of curvilinear street patterns, and connection of new development to
existing circulation systems at multiple locations. At a minimum, pedestrian and bicycle
connections need to be made. They also find, however, that providing increasingly higher levels
of connectivity resulted in diminishing returns. As a result, the most cost-effective level of
interconnectivity would be achieved at about 10 to 16 street connections per mile along the
arterial street. The authors acknowledge the potential impacts as a result of increased
interconnectivity, including intrusion of regional traffic into neighborhoods and the reduction of
arterial capacity as a result of the increase in intersections. The study suggests that neighborhood
traffic management plans might be needed to address traffic and speeding issues as a result of
connectivity.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
25
E. School Transportation/Location
A number of previously reviewed studies (Wallwork, Victoria Transport Policy Institute, and
Zelinka and Brennan) suggest that locating schools in and adjacent to residential neighborhoods
provides benefits to the community, primarily enhancing safety, as well as improving walkability
and health. School design and siting, however, can also significantly affect students’ safety,
development, learning, and health.
Some issues of concern are discussed in the United States Environmental Protection Agency’s
article Travel and Environmental Implications of School Siting. The concerns include:
• In 1969, 48 percent of all students walked or biked to school and nearly 90 percent of
students living within a mile of school walked or biked. In 2001, 16 percent of all
students walked or biked to school and only 31 percent of students living within one mile
walked or biked.
• A traffic engineer in Santa Rosa, California, estimated that the number of cars on the road
between 7:15 a.m. and 8:15 a.m. increases by 30 percent during the school year.
Evidence shows that increased automobile travel contributes to ozone and other air
pollutants. There is overwhelming evidence linking air pollutants to respiratory ailments
in children, particularly asthma. There is, also, strong evidence to show that reducing
automobile use can improve health: during the 1996 Atlanta Olympic Games when
driving was reduced, ambient ozone levels fell by 27.9 percent, and emergency-room
visits for asthma dropped by 41.6 percent.
• Minimum acreage requirements adopted at the state and local levels imply that schools
not meeting the thresholds are inadequate. Funding formulas favor building new schools
rather than renovating existing schools.
Mayer Hillman presented the paper The Impact of Transport Policy on Children’s Development
in 1999, which focused on activities in England. The conclusions, however, are highly relevant
to the United States. In addition to the health effects on children as a result of reduced physical
activity, the paper highlights the affect on children due to their loss of independence as a result of
being constantly driven to all leisure and school journeys. Some of the impacts include:
• More and more children, up to an ever-later age are being escorted, usually in cars, on all
journeys including trips to school. To some extent, this is as a result of our built
environment being unsafe for children. While most children own a bicycle, few are
allowed to use it as a means of transportation.
• Children have fewer opportunities to learn from exposure to the natural and man-made
world – opportunities and stimuli crucial to children’s understanding of the real world.
They are deprived of opportunities to develop practical skills, as well as social and
emotional skills.
• This creates a “catch-22,” as children have fewer opportunities to learn road skills during
childhood. Previous generations often acquired these important skills while walking and
cycling along relatively safe local streets. If they do not acquire these necessary skills,
our communities become even more dangerous for children.
• Children are much more likely to be killed as a passenger in a car accident than as a
pedestrian.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
26
•
•
•
•
•
Children gain experience from making their own decisions without adult supervision,
learning how to act responsibly and how to assess the motives of strangers. Additionally,
they gain self-esteem and self-confidence by being reliable, punctual, and contributing to
family life (e.g., running errands). When accompanied by an adult, a child’s instinct is to
leave decisions to that adult.
Dependence on car travel also tends to limit children’s participation in extra-curricular
activities.
Although Safe Routes to School programs are a step in the right direction, we need to
place a greater emphasis on safe communities for children. According to Hillman,
children make many more journeys in their free time than they do to and from school,
and 90 percent of child fatalities occur on those other journeys.
A British study finds that when traffic calming measures were introduced, 50 percent
more children were allowed to walk to school on their own.
Placing bus stops near liquor stores, bars, adult-oriented uses and other undesirable uses
should be avoided [this also seems highly applicable to schools and other children’s
facilities].
Some national school trends were compiled by Paul Abramson of Stanton Leggett & Associates,
as reported by Stephanie Moody and David Edgell in Planning Delaware’s School Needs:
Issues of Location, Design and Infrastructure, and include:
• The population of school-age children is rising and this trend is not expected to change in
the foreseeable future.
• Changes in programming and curriculum, including mainstreaming students with
disabilities and cooperative learning, often result in the need for additional space and
additional space per child within schools.
• Schools need space for technology, as well as the wiring and other infrastructure required
to provide technology. More space per child is now needed to accommodate computers
and peripherals within the classroom.
• Many school buildings are in very poor condition. Statistics show that children who
attend schools in poor condition score lower on achievement tests than children who
attend schools in good condition.
• There is a general public will to improve schools and education.
Also, according to Abramson, the ideal new school will:
• Keep school capacity small, with no more than 450 students in elementary schools and no
more than 600 students in middle and high schools.
• Increase space per child to 120 sq ft/elementary child, 140 sq ft/middle school child, and
160 sq ft/high school student.
• Expand upwards, using the roof if needed for play areas when not enough acreage is
available in an appropriate location.
• Build school facilities that also serve the local community. Incorporate health facilities,
childcare centers, job training, social services, recreational activities, libraries, and
conference and meeting facilities.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
27
According to Kenneth Stevenson, Ed.D., as reported in The Future of School Siting, Design and
Construction in Delaware (Hunter and Sawak), there are six factors that are driving 13
educational trends in the United States. The factors are 1) Birth Patterns, 2) Aging Populations,
3) Family Status, 4) Value of Education, 5) Technology, and 6) Culture. The following trends
have emerged:
• The disappearance of attendance lines/zones as school choice, charter, and magnet
schools cross over traditional district boundaries.
• A return to smaller neighborhood schools possibly leading to resegregation.
• Schools developing unique personalities and curriculum themes.
• Continued reduction of pupil/teacher ratios.
• Technology-dominated schooling.
• Schools as full-service agencies, also providing community services.
• Narrowly defined curricula, especially given the move towards increased accountability.
• Schools focused on learning and teaching styles, accommodating distinct learning styles.
• Students as workers, with teachers now being considered facilitators of the education
process, rather than keepers of knowledge.
• Extension of school time with extended and year-round schools, giving children more
time to learn.
• Paperless schools.
• Grades grouped differently, moving towards K-12 schools.
• No school as we now know it – moving towards virtual schools and education as a
commodity.
Based on the emerging trends, Stevenson makes the following recommendations:
• Use schools as community centers. It is especially important that the aging population
feel like they have a stake in education.
• Create school facilities that are 1) highly flexible, 2) safe and secure, 3) support existing
and future technology, 4) durable, 5) used 16 hours/day year-round, and 6) inviting and
important to the community as a whole.
In 1994, Prevention magazine published Blueprint for a Walkable Community: Florida’s 12Step Program, which included the following recommendations related to schools:
• Step 6: Simplify Median Crossings. Build landscaped medians into existing roads to
allow pedestrians to cross wide roadways more securely. Focus on high-volume
pedestrian areas around schools, entertainment areas, malls, and residential
neighborhoods.
• Step 7: Make Walking to Schools Safer. Identify specific places for buses and cars to
drop off children, away from pedestrian areas. Designate areas for children to cross
streets safely with as little contact with vehicles as possible. Design all roadways around
schools to automatically slow traffic.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
28
The book SafeScape: Creating Safer, More Livable Communities through Planning and Design
(Zelinka and Brennan) suggests the following safety recommendations relating to school design
and location:
• Create clear boundaries/borders to enhance public spaces, define ownership, and
encourage appropriate behavior. However, make sure they are carefully designed and
maintained not to obstruct walkways, visibility, and sightlines, or create a negative
(prison-like) impression.
• Maintain playgrounds, sidewalks and buildings to maximize perceptions of safety.
Graffiti, trash and general disrepair are signs that nobody cares or is watching.
• Locate doors, windows, and other activity areas so that they always face the street.
• Locate playgrounds where visible from the school and neighboring buildings or the street
for continuous monitoring.
• Separate pedestrian and vehicular movement, especially in parking lots and where
entrances and driveways cross sidewalks.
• Locate schools and churches within/adjacent to residential neighborhoods to strengthen
neighborhood ties and increase perceptions of safety due to the activity around the
school, especially during the day. The institutions enhance the community through
shared facilities such as meeting rooms. Similarly, other beneficial public facilities
include senior centers and police stations.
Developed by Barbara Kent Lawrence and Jannell Weihs, the Table: State Guideline
Information provides the site size formulas for 49 states according to the type of school
(elementary, middle, and high school). Of the 49 states reviewed, 23 do not have specific
recommendations for acreage of school sites. Most states’ formulas consisted of a base acreage
plus additional acreage based on the number of students. In Delaware, elementary schools are to
be ten acres plus one acre per 100 children, middle school sites are to be 20 acres plus one acre
per 100 students, and high schools are to be 30 acres plus one acre per every 100 children.
Delaware is not included in the tables below.
Table 3: Elementary School Site Size Formulas
Formula
Number of States
3 acres + 1 acre/100
4 acres + 1 acre/100
5 acres + 1 acre/240
5 acres + 1 acre/100
7 acres + 1 acre/100
10 acres + 1 acre/100
Up to 8 to 18 acres
9.6 acres/450 students;
13.8/750; 17.6/1200
10 acres
5+1/100 to 20+1/100
10 to 15 acres +1/100 +other
Size for 450 Children
1
2
1
8
1
8
1 (Arizona)
1 (California)
7.5 acres
8.5 acres
7 acres
9.5 acres
11.5 acres
14.5 acres
8-18 acres maximum
9.6 acres
1 (Connecticut)
1 (Maine)
1 (Minnesota)
10 acres
9.5 to 24.5 acres
14.5+ to 19.5+ acres
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
29
Table 4: Middle School Site Size Formulas
Formula
Number of States
10 acres + 1/100
11 acres + 1/100
12 acres + 1/100
15 acres + 1/100
20 acres + 1/100
Up to 18 to 36 acres
17.4 acres/600 students;
20.9/900; 23.1/1200
15 acres
10 acres/300 students; 15/400;
20+1/100 over 500
10+1/100 to 25+1/100
25 to 35 acres +1/100 +other
7
1
1
3
7
1 (Arizona)
1 (California)
1 (Connecticut)
1 (Idaho)
1 (Maine)
1 (Minnesota)
Table 5: High School Site Size Formulas
Formula
Number of States
10 acres + 1/100
15 acres + 1/100
20 acres + 1/100
30 acres + 1/100
35 acres + 1/100
Up to 30 to 70 acres
33.5 acres/1200 students;
44.5/1800; 52.7/2400
20 acres
20 acres/400 students; 25/800;
30+1/100 over 800
15+1/100 to 30+1/100
35 to 60+1/100 + other
20 acres/400 students; 25/800;
30 over 800
4
3
3
8
1
1 (Arizona)
1 (California)
1 (Connecticut)
1 (Idaho)
1 (Maine)
1 (Minnesota)
1 (Wyoming)
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
Size for 600 Children
16 acres
17 acres
18 acres
21 acres
26 acres
18 to 36 acres maximum
17.4 acres
15 acres
26 acres
16 to 31 acres
31 to 41 acres
Size for 1200 Children
22 acres
27 acres
32 acres
42 acres
47 acres
30 to 70 acres maximum
33.5 acres
20 acres
42 acres
27 to 47 acres
47+ to 77+ acres
30 acres
30
F. Trails
Most trails are separate, off-road facilities designed for pedestrians and bicyclists, but may also
be designed for equestrians and in-line skaters. Often used for recreational purposes, shared use
paths are increasingly being advocated for non-motorized transportation purposes.
In the article Rails and Trails: Design of Trails, the Pedestrian and Bicycle Information Center
provides insights regarding trail users and recommended standards for design. The center
acknowledges that 1) trails are seldom used in one direction of travel or by one category of user;
2) trails need maintenance, and maintenance vehicles may damage narrow trails; trail users,
especially cyclists, have a low tolerance for delay; bicyclists have a strong desire to maintain
momentum and may feel as if traffic regulations do not apply to them; and younger trail users
may not be experienced dealing with traffic. With these observations in mind, the center
provides the following guidelines:
• Shared use paths (trails) should be a minimum of 10 feet wide to accommodate multiple
users traveling in both directions. Urban trails may require 12 feet or more, and trails
with heavy use or large numbers of in-line skaters may need to be at least 14 feet. In
rural areas with no walkers or joggers, trails may be reduced to eight feet wide. Two feet
of clear space on either side of the trail is recommended so users can avoid signs, shrubs,
walls, etc. This total width should be maintained through bridges, tunnels, etc.
• Asphalt or concrete surfaces are preferred for heavily used trails and trails with in-line
skaters. However, paved trails will raise the speed of bicyclists, which may be an issue in
areas with heavy pedestrian use. Crushed limestone is adequate for low-use facilities, but
is more prone to flood damage. Some hard surface trails have a parallel soft surface for
jogging or equestrian use.
• The best trails avoid sudden or sharp turns, but are not completely straight either.
• Slopes should be kept to less than five percent as much as possible.
• Railings, fences, or barriers should be a minimum of 42 inches tall.
• Intersections between the path and roadways must be carefully and consistently designed:
crossings at 90 degrees, consistent designs, sound engineering and markings using
MUCTD standards. The objective is to make trail users as visible and predictable as
possible to motorists and each other.
• Trails should not be located immediately adjacent to roadways, as this encourages wrongway traffic, makes users less visible to motorists, and sets up conflicts with driveways
and intersections. The minimum recommended separation is five feet horizontally or 42
inches vertically, by barrier or railing.
In Shared Use Paths (Trails), the Pedestrian and Bicycle Information Center offers more insights
and guidelines for trail design including:
• Trails are an addition to, not a substitute for, the roadway network. Trail users will still
need to use roads and sidewalks traveling to and from the trail.
• Shared use paths function best when they are in their own right-of-way. One study
recommends bicycle lanes or shared roadways instead of multi-use paths when there
would be more than eight crossings per mile.
• Paths are used by a wide variety of users including pedestrians, joggers, in-line skaters,
fitness walkers, and people with dogs or strollers, bicyclists, and equestrians.
Mobility Friendly Design Standards: A Framework for Delaware
31
DRAFT: February 2004
•
•
•
•
•
•
•
Connections between the trail access points and local transit service can encourage trail
use and boost transit ridership.
Adequate site and stopping distances should be provided.
Design speed should be set at 20 mph minimum, 30 mph where downgrades exceed four
percent, and 15 mph on unpaved paths.
Poor drainage can ruin a good trail. A minimum cross slope of two percent is
recommended, no greater than three percent to ensure wheelchair accessibility. Slope the
trail in one direction, rather than having a crown, and place grates, utility covers, etc. out
of the travel path of bicycles, and preserve natural groundcover adjacent to the path to
prevent erosion. The path surface must be smooth and evenly graded.
Trails in urban and suburban areas often serve travel needs both day and night, and need
to be adequately lighted.
At intersections with roadways some paths may be mistaken for roads. Therefore paths
need to be clearly marked and signed in both directions to discourage unauthorized
motorized access. Other options include using carefully located bollards and medians, or
splitting the trail into two approaches with a planted triangle in between.
Signage and striping should be used to provide information relating to location, warnings,
upcoming intersections, and expected behavior.
In Barrier-free Exterior Design: anyone can go anywhere, Robinette explains the importance of
providing railings, curb or rope along the edge of trails to help define the trail and warn of
danger areas, in order to provide a barrier-free environment for the visually impaired. Signs
should be posted to describe the trail’s the length, location of special areas such as rest rooms,
location and height of signs along the route (to accommodate the blind), meaning of special
signals such as textural changes, and dangerous areas.
In Designing Sidewalks and Trails for Access Part II of II: Best Practices Design Guide,
(Kirschbaum et al.) design guidelines are provided for trails and shared use facilities, which
contribute to universal accessibility.
•
Trails in General
o Trail width depends on the trail’s intended type, use and user groups, amenities,
barriers, and furniture.
o Trails are broken into three components: trailhead, trail corridor, and trail
elements.
o Trails should be wide enough to allow access to individuals with all types of
disabilities, such as individuals using wheelchairs, hand power cycles, tandem
cycles, or horses.
o Barriers, if used on a shared use path or recreational trail where bicycles are
permitted, should be spaced 60 inches apart. This will accommodate all types of
bicycles wheelchairs, scooters, and walkers. If the trail is restricted to
pedestrians, then the minimum passage space between barriers should be 36
inches.
o Trail elements, such as water fountains, bathrooms, and fire rings, should provide
enough clear space for the maneuvering of mobility devices.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
32
o Surface materials should be consistent with the intended use of the trail and the
surrounding area. A rustic backwoods trail through the wilderness, for example,
should not be designed as a paved shared use path.
o Surface materials should be consistent throughout the trail (i.e., a wide paved trail
should not come to a half-log crossing over a stream or require wading through
the stream).
o Soft or unstable surfaces should be avoided, but never allowed for more than 45
feet in accessible areas, and should be avoided around elements that would be
used by the disabled.
o A description of the surface should be provided at the trailhead.
o Waterbars stretch across the width of the trail and direct water to the path edge.
They are typically constructed of wood, rocks, or rubber. Wood and rocks tend to
be obstacles for individuals using mobility devices.
o Lighting should be evenly distributed, focused on sidewalks, and shine down, not
out. Reflective paints and markings amplify the benefits of lighting.
o Trails in extreme climates should provide rest areas or shelter from harsh
conditions.
•
Shared Use Paths
o Paths should be a minimum of ten feet wide, eight feet if limited use, and 12 to 14
feet where use is heavy.
o Include a level area two feet wide on either side of the path.
o If the path or sidewalk is less than 60 inches wide, then provide periodic passing
spaces of at least 60 X 60 inches.
o Generally, use surface materials such as asphalt or concrete, crushed stone or soil
stabilizing agents mixed with native soils or aggregate.
o Material affects path use, so designers must consider firmness, stability, and slip
resistance.
o Asphalt and concrete are considered firm and stable in all conditions, crushed
limestone is considered firm and stable in most conditions.
o If a natural appearance is desired, consider using synthetic bonding materials.
o When dry, asphalt and concrete are fairly slip-resistant, but designers need to
consider the typical weather conditions where the path will be installed.
•
Recreational Trails
o Recreational trails should have a minimum clear trail width of 36 inches.
o Passing spaces of 60 X 60 inches should be provided at least every 200 feet where
the clear trail width is less than 60 inches.
o Firmness, stability, and slip resistance are of particular importance to individuals
using mobility devices.
o Trails should be surfaced with firm and stable materials. Soft trail surfaces should
be avoided.
o Crushed stone, fine, packed soil, and other natural materials can be firm and
stable.
o Brushed concrete and asphalt are slip-resistant under dry conditions.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
33
o Soil stabilization products mixed with natural surfacing materials will create a
slip-resistant surface.
o Paved surfaces such as asphalt and concrete, or soils or aggregates with
stabilizing agents, will be firm and stable in both wet and dry conditions.
•
Guidelines for Grade Changes
o Minimum height for railings on shared use paths should be 42 inches. In some
cases, a gripping surface for pedestrians is helpful.
o Steps create a barrier for individuals in wheelchairs and should not be included in
new construction.
o Where steps already exist, alternate routes should be created. Signage should be
installed at the trailhead indicating the presence of steps, and barriers should be
installed around the steps to ensure appropriate use. Wheel tracks along the stairs
may encourage bicyclists to use the stairs.
o Flights of stairs should be set apart from one another and the height should be
minimal if steps must be used. Wheelchair users, however, will still require
assistance.
o Switchbacks, commonly used for steep terrain, should be less than five-percent
slope, follow natural drainage patterns to ensure a constant firm and stable
surface, and include natural or other barriers at the edges of the path.
•
Maintenance of Trails
o Maintenance is required under ADA to keep trails in compliance.
o Designers need to consider the types of emergency situations likely to occur and
the vehicles used for emergencies and maintenance.
o Typical shared use path maintenance issues are similar to sidewalks, namely step
separation, badly cracked pavement, spalled areas, settled areas that trap water,
tree-root damage, and vegetation overgrowth.
o Recreational trail systems require regular inspections to assess and catalog
problems.
o Typical recreational trail maintenance activities include checking the structural
integrity of built features, keeping trail surfaces free of obstacles and hazards,
clearing and maintaining drainage features to minimize trail erosion and
environmental damage (e.g., clearing channels, maintaining cross slopes on the
trail bed, cleaning drainage dips or water bars, clearing parallel ditches, cleaning
culverts through or the beneath trail), cutting brush, maintaining the trail in a
condition that can be negotiated by users, extending the trail to its original width,
filling ruts and holes, and restoring raised approaches for bridges.
o Users should have convenient means of reporting problems with timely responses.
In SafeScape: Creating Safer, More Livable Communities through Planning and Design (Zelinka
and Brennan) recommendations are provided for designing and locating trails to enhance user
safety. The recommendations include:
• Clearly articulate rules and directions and provide appropriate directional and locational
signage.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
34
•
•
•
•
Provide clear boundaries and borders to enhance pedestrian corridors, define ownership,
and encourage appropriate behavior. Boundaries must be carefully designed and
maintained so as not to obstruct trail visibility and sightlines.
Maintain trail facilities to maximize perceptions of safety. Graffiti, trash, and general
disrepair are signs that nobody cares or is watching.
Locate trails where they will be visible from neighboring buildings or the street as much
as possible.
Avoid pedestrian tunnels and bridges where possible. When necessary, they should be as
short as possible, straight, wide, and well lighted. Bridges should allow for full visibility
from within and without.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
35
G. Effectiveness
How effective are the best practices? Few have been examined in great detail. In fact, most of
the data on effectiveness is anecdotal. Some researchers, however, have attempted to quantify
the effectiveness of the recommendations.
Factors that Influence Modal Choice
A number of specific factors have been found to affect travelers’ choice of travel mode,
including: parking, transit amenities, pedestrian facilities, transit service, street trees, short block
lengths, traffic calming, and density. Less proven are community design philosophies including
transit- and pedestrian-oriented design, traditional neighborhood design, and mixed-uses. Socioeconomic factors, also, greatly influence mode choice.
• The article Pedestrian- and Transit-Friendly Design: A Primer for Smart Growth
(Ewing) highlights studies showing that downtown pedestrian counts in small cities fall
as the amount of open parking increases.
• Kikuchi et al. in Micro-Level Transit Accessibility Study identify a number of specific
amenities that improved transit ridership, including the presence of bus shelters, seating,
and lighting. The authors find a correlation between these amenities and ridership.
Ridership increases when more of these amenities are present.
• Kikuchi et al. find that the presence of pedestrian paths to bus stop and nearby signalized
crosswalks contributed to greater transit ridership.
• In the article A micro-analysis of land use and travel in five neighborhoods in the San
Francisco Bay Area, Moktarian R. Kitamura and P.L. Laidet examine the effects of land
use and attitudinal characteristics on travel behavior for five diverse neighborhoods in the
San Francisco Bay Area. The authors find that neighborhood characteristics add
significant explanatory power when socio-economic differences are controlled.
Specifically, the presence of sidewalks is significantly associated with trip generation by
mode and modal split.
• The U.S. Environmental Protection Agency (EPA) in Travel and Environmental
Implications of School Siting concludes that the proportion of arterials and collectors (the
model does not include local streets) with sidewalks is the second most significant
influence on walking trips to school. A 25-percent across-the-board reduction in sidewalk
coverage resulted in 0.8-percent decrease in walking mode share, from 4.5 to 3.7 percent
of trips to school.
• The Pedestrian and Bicycle Information Center, in the article Shared Use Paths (Trails),
finds that connections between the trail access points and local transit service can
encourage trail use and boost transit ridership.
• Kikuchi et al. find, also, that the level of transit service is important to the level of
ridership. The study indicates the specific characteristics that improve transit ridership
include the frequency of service, number of routes served at the stop, and availability of
network and schedule information at the individual stop. The more characteristics that
are present, the higher ridership will be.
• Stone et al. note the effects of a greatly improved transit system on the cities of Seattle,
Portland, San Diego, and Los Angeles. For example, trips into downtown Seattle shifted
heavily toward transit use and bicycling, with improved facilities and strong support from
political groups. Increases in walking trips from the nearby Capital Hill District were also
Mobility Friendly Design Standards: A Framework for Delaware
36
DRAFT: February 2004
•
•
•
reported. Additionally, transit gained high-volume ridership overnight when it introduced
its 16-mile “Red Line” and “Tijuana Trolley” in San Diego, which started its efforts with
$60 million.
In the article A micro-analysis of land use and travel in five neighborhoods in the San
Francisco Bay Area (Kitamura and Laidet), the authors find, also, that measures of public
transit accessibility are significantly associated with trip generation by mode and modal
split.
In the article Travel and Environmental Implications of School Siting, the EPA cites a
study by Tracy McMillan (“The Influence of Urban Form on a Child’s Trip to School,” a
paper presented at the Association of Collegiate Schools of Planning Annual Conference,
Baltimore, 2002) indicating that walking or bicycling to school is more likely when
certain pedestrian-friendly design features, such as the presence of street trees and short
block lengths are present.
Hillman, in the paper The Impact of Transport Policy on Children’s Development, notes a
British study that finds that when traffic calming measures were introduced, 50 percent
more children are allowed to walk to school on their own.
A number of sources discussed the effect of density on mode choice.
• J. Miller and Hoel, in The “smart growth” debate: best practices for urban
transportation planning, cite studies that confirm that compact density can reduce
automobile trip rates when all other factors are controlled, but the reduction is marginal.
The authors cite another study that concludes that demand for transit services is affected
more by the quality of neighborhoods than proximity of compact development to transit
stations.
• Giuliano, in the article Land Use Policy and Transportation: Why We Won’t Get There
From Here, states that density policies that could be implemented will be swamped by
larger trends, such as the continued decentralization of population and employment,
rising incomes, and the growing impact of telecommunications technology.
• Kikuchi et al. note, also, in the article Micro-Level Transit Accessibility Study that on the
land use side, the presence and density of commercial activity close to a bus stop and/or
the density of homes within 1/4 mile of the stop affected ridership, with greater densities
correlating to greater ridership.
• Kitamura and Laidet find that measures of residential density are significantly associated
with trip generation by mode and modal split. Attitudes, however, appear to be more
strongly and perhaps more directly associated with travel than are land use
characteristics, suggesting that land use policies promoting higher densities may not alter
travel demand.
• EPA concludes that, after controlling for travel time, density and land use mix do not
appear to have had any effect on choice of travel mode to school.
• Numerous studies dating back 30 years or more, however, have proven the relationship
between land use densities and transit usage. We will not restate them all here, but
include: Rail-oriented Office Development in California: How Successful? (Cervero),
Impacts of Mixed-Use and Density on the Utilization of Three Modes of Travel: SingleOccupant Vehicle, Transit and Walking (L.D. Frank and Gary Pivo), and A microanalysis of land use and travel in five neighborhoods in the San Francisco Bay Area
(Kitamura and Laidet).
Mobility Friendly Design Standards: A Framework for Delaware
37
DRAFT: February 2004
Conclusions regarding the effectiveness of new urbanism/neotraditional design, pedestrian and
transit-oriented design, and mixed-uses have differed:
• J. Miller and Hoel conclude that public policies aimed at eliminating sprawl, such as new
urbanism and holistic transportation planning have been ineffective due to their failure to
recognize the explicit choices made by transportation consumers over the last 50 years.
They cite a study that concludes that there does not seem to be a direct link in the
correlation of additional roadway capacity and inducing additional trips.
• Giuliano concludes that the effect of pedestrian-friendly or transit-oriented neighborhood
design is uncertain. While some studies show a link between the strategies and nonmotorized travel, no study has been able to link the strategies to changes in auto use.
• Petersmark and Wilkerson in the article Land Use Affects Public Health state, “Research
has demonstrated that suburban residents drive twice as far, walk and cycle one-third as
often, consume twice as much energy, and produce twice as much air pollution as their
urban counterparts who live where land use tends to be mixed.”
• E. Miller and Shalaby in Evolution of Personal Travel in Toronto Area and Policy
Implications state that empirical research has shown that coordinated land use and
transportation planning designed to emphasize and promote transit usage works. In
addition, projects in Toronto have demonstrated that it is possible to maintain a strong,
vital, and livable urban core that is the economic heart of an extensive urban system and
is serviceable throughout the extent of the urbanized area by an attractive, cost-effective
transit system capable of attracting a majority of commuters, successfully competing with
the automobile.
• Kikuchi et al. report in Micro-Level Transit Accessibility Study that the amount of nearby
trip generators encouraged greater transit ridership.
• Kitamura and Laidet find that measures of mixed land use are significantly associated
with trip generation by mode and modal split. The authors conclude, however, that
attitudes are certainly more strongly, and perhaps more directly, associated with travel
than land use characteristics, suggesting that land use policies promoting land use
mixtures may not alter travel demand.
• Butler et al., in the book Planning for Street Connectivity, determine that infill and
redevelopment projects can be used to increase local connectivity, but the overall effect is
usually insignificant or marginal at best.
• EPA, in the 2003 article Travel and Environmental Implications of School Siting, cites a
study by Tracy McMillan (“The Influence of Urban Form on a Child’s Trip to School,”
presented at the Association of Collegiate Schools of Planning Annual Conference,
Baltimore, 2002) indicating walking or bicycling to school is more likely when homes are
within a mile of school, and less likely when households have more licensed drivers to
provide rides. Similarly influencing travel behavior, but of secondary importance, are
certain pedestrian-friendly design features, such as mixed land uses. Accessibility (the
number of trip attractors/generators), another built environment variable, influenced
school bus ridership. The less accessible the school or home location (and the fewer
other land uses in close proximity), the more likely that students would take the school
bus. This study concludes that locating schools close to residents increases the viability
of walking and biking to school by as much as 13 percent, reducing the total number of
vehicular trips. In addition, the total number of vehicular miles traveled is reduced,
further reducing auto emissions by at least 15 percent.
Mobility Friendly Design Standards: A Framework for Delaware
38
DRAFT: February 2004
Socio-economic and Attitudinal Factors
Some socio-economic factors were determined to affect mode choice:
• EPA finds that students from households with higher incomes or more vehicles per capita
are less likely to walk to school. Students holding driver’s licenses are less likely to use a
school bus than students without licenses.
• Kitamura and Laidet conclude that attitudes are certainly more strongly, and perhaps
more directly, associated with travel than are land use characteristics.
Additional Effectiveness Data
• Ewing reports in Pedestrian- and Transit-Friendly Design: A Primer for Smart Growth
that nine percent is the upper limit on the amount of land area devoted to parking, beyond
which people sense that the environment is no longer people-oriented but has become
car-oriented. Also, accident rates are significantly lower where marked crosswalks are
provided and crossings are lighted. Additionally, studies disagree about how important
special paving is to the overall pedestrian environment.
• According to the article Traffic Calming “How to Make Streets More Livable”
(Wallwork), after-the-fact traffic control techniques such as posting unrealistic speed
limits, using all-way stop signs at intersections, and police enforcement campaigns fail to
produce sustainable results.
• Also, according to Wallwork, there has been no correlation shown between neighborhood
street layout and the incidence of crime. Even gated communities are known to be the
targets of crime and police chiefs report that a significant proportion of all crimes are
found to occur between family members or neighbors. However, having many access
points encourages more on-street activity, which is a deterrent to crime.
• Ewing, in Traffic Calming: State of the Practice, provides effectiveness data for specific
traffic calming measures, based on changes in speed, traffic volume, and accidents. This
data is summarized in Table 6.
Table 6: Impacts of Selected Traffic Calming Measures
Measure
Speed Impacts
Average change
(mph/percent)
-7.7/-23 percent
-6.6/-18 percent
Volume Impacts
Average percent
change
-22 percent
-12 percent
Collision Impacts
percent change
Raised Intersection
-0.3/-1 percent
-----
-----
Mini-circle
-3.9/-11 percent
-----
Circle
Narrowing
-----2.6/-4 percent
-5 percent
-10 percent
-29 percent to -73
percent **
---------
Full Closure
-----
-44 percent
-----
Half Closure
-6.0/-19 percent
-42 percent
-----
Diagonal Diverter
-1.4/-0 percent
-35 percent
-----
14-foot Hump
22-foot Table
-41 percent
-45 percent
** Depending on design
Source: ITE Traffic Calming: State of the Practice, compiled by DelDOT in the Traffic Calming Design Manual.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
39
•
•
Ewing discusses, also, the effectiveness of some regulatory measures often requested for
traffic calming purposes including stop signs that actually can cause an increase in
accidents, have poor compliance, effect little or no mid-block speed reduction, and tend
to encourage rolling, rather than complete, stops. Turn restrictions are most effective
when limited to peak hours. If continuous restrictions are desired, half closures are
preferred to restrict volume. Without enforcement, only 50 percent of vehicles will
comply. With active enforcement (constant police presence) compliance is increased to
80 percent. One-way streets do not address speeding problems, having had limited
successes and many violations. Half closures are recommended instead of or in addition
to one-way restrictions.
Daisa et al., in the study Does Increased Street Connectivity Improve the Operation of
Regional Streets? Case Studies from the Portland Metro Regional Street Design Study,
conclude that an interconnected street system improves traffic flow on arterial streets.
The study finds that interconnectivity reduces traffic volumes on arterials, vehicle hours
of delay, vehicle miles of travel, and average trip lengths. The model indicates that a
portion of long-distance regional travel will use parallel collector and local streets to
bypass congested intersections and streets if the parallel route offers equal or better travel
time. However, the majority of long-distance travel remained on the arterial streets. The
authors recommend that neighborhood traffic management plans may be needed to
address traffic and speeding issues due to connectivity. However, they find, also, that
providing increasingly higher levels of connectivity resulted in diminishing returns.
Therefore, the authors determine that the most cost-effective level of interconnectivity
would be achieved between 10 to 16 street connections per mile along the arterial street.
Additional Considerations Regarding Effectiveness
In the article Walkable Suburbs? An Evaluation of Neotraditional Communities at the Urban
Edge, Southworth reviews Kentlands, a neotraditional community near Gaithersburg, Maryland.
The community was designed in 1988 with 1,600 dwelling units and a projected population of
5,000. Housing types include single-family houses, row houses, condominiums, and apartments
(many garages have living units or “granny flats” above them). The community is dependent
upon traditionally developed Gaithersburg for most services and jobs. The mix of uses includes
churches, an elementary school, a day care center, a library, and a community recreation center.
The dense distribution and interconnection of a wide variety of spaces and destinations in
Kentlands provides significant access and activity opportunities for children, teens, and the
elderly.
Southworth concludes that the access to retail and office uses seen in traditional development has
not been truly achieved. He states that the model is essentially anti-urban and excludes elements
that are typically necessary to make a metropolitan region work. Towns and urban areas must do
much more than house middle-income people. They usually include housing for the low-income
population, commercial and industrial space, cemeteries, waste-disposal sites, and many other
uses that planned suburbs typically exclude. In general, the developments offer instant identity
and sense of community by controlling the built form. It remains to be seen, however, whether
this image-based development will prove sustainable and serve the needs of future residents.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
40
In the article Land Use Policy and Transportation: Why We Won’t Get There From Here,
Giuliano points out that most households have no incentive to locate in dense, high-cost centers
due to rising incomes and a willingness to give up accessibility for space. The households that
prefer urban living, such as young, single persons and affluent, empty-nesters support highdensity policies, but are niche markets that cannot sustain the urban environment.
Sarker et al., in Impact of Transportation Infrastructure Development on Modal Choice, note that
it is necessary to limit the supply of auto-related transport with respect to demand while
improving efficient and sustainable alternative transportation systems.
According to Butler et al., efforts to add bicycle and pedestrian paths to existing residential
developments can generate considerable resistance from nearby residents.
Stone et al. point out that voters in Los Angeles taxed themselves heavily to start rebuilding the
once-famous transit system. Portland, however, is reclaiming views of mountain landmarks with
the successful introduction of an extensive system of buses and light rail.
Finally, the article Transit Oriented Development: Using Public Transit to Create More
Accessible and Livable Neighborhoods (Victoria Transport Policy Institute) documents a series
of predictions based on available data regarding the effectiveness of transit-oriented design and
some of its components. The Institute cites a major study by 100 Friends of Oregon predicting
that TOD would reduce single-occupant vehicle commuting by 22.5 percent, increase transit and
non-motorized travel by 27 percent, and reduce congestion by 18 percent. A second study by
Cambridge Systematics predicts that TOD would reduce auto travel by 20 to 25 percent,
compared with conventional development. A third study predicts the successfulness of various
types of development as outlined in the table below.
Table 7: Travel Impacts of Land Use Design Features (Dagang 1995)
Design Feature
Reduced Vehicle Travel
Residential development around transit centers
Commercial development around transit centers
Residential development along transit corridor
Commercial development along transit corridor
Residential mixed-use development around transit centers
Commercial mixed-use development around transit centers
Residential mixed-use development along transit corridors
Commercial mixed-use development along transit corridors
Residential mixed-use development
Commercial mixed-use development
10 percent
15 percent
5 percent
7 percent
15 percent
20 percent
7 percent
10 percent
5 percent
7 percent
The Victoria Transport Policy Institute reviewed, also, the benefits and costs of transit-oriented
design. Benefits of TOD included increased transit service efficiency, higher property values,
increased commercial activity, increased tax revenues, and significant declines in average
vehicle ownership, vehicle travel, and vehicle expenditure per household. Specifically identified
benefits of TOD include congestion reduction, road and parking savings, consumer savings, and
increased transport choice, road safety, environmental protection, efficient land use, and
community livability. The Institute concludes that consumer expenditures on motor vehicles
provide little economic return. For example, an investment of $10,000 on a motor vehicle
Mobility Friendly Design Standards: A Framework for Delaware
41
DRAFT: February 2004
provides only $910 in equity, compared with $4,730 in equity for the same investment in
housing, suggesting potential consumer savings from TOD. The costs of TOD include
incremental transportation expenditures, such as facility improvements, and disamenities
associated with higher-density development, such as increased local traffic congestion and noise
exposure.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
42
PART III. DELAWARE AND NEW CASTLE COUNTY ACTIVITIES
During the 1990s, as the population boomed along with vehicle ownership and vehicle miles
traveled (VMT), the Delaware Department of Transportation (DelDOT), Wilmington Area
Planning Council (WILMAPCO), and New Castle County, began to look for new tools to
alleviate traffic congestion. A number of studies looked at the connection between land use
issues and transportation in an effort to provide better access to transportation for people
throughout the state and improve the variety of mode choices available. This section reviews
the policy documents that were adopted, research and recommendations developed for Delaware
and New Castle County, and steps taken toward implementation of the recommendations through
design manuals, regulations, and adopted codes.
A. Transportation and Land Use Policy
Many Delaware agencies have written and adopted policy documents expressing the desire to
improve mobility using all modes of travel through land use and transportation techniques, using
all modes of travel. In 1996, WILMAPCO adopted the 2020 Metropolitan Transportation Plan,
Connections to the 21st Century, and in 2003 reaffirmed the concepts in the update Opening the
Door to Change. New Castle County adopted a Comprehensive Development Plan in 1997 and
an update in 2002. DelDOT adopted the Statewide Long Range Transportation Plan
Transportation and Delaware’s Future in 1997 and updated the plan in 2002. All of the policy
documents acknowledge the relationship between land use and transportation planning, and all
express support for and the intention to implement mobility friendly practices.
State Strategies
In 1999, the Governor’s Cabinet Committee on State Planning Issues adopted Shaping
Delaware’s Future: Managing Growth in 21st Century Delaware, Strategies for State Policies
and Spending. It was written by the Office of State Planning Coordination (OSPC) in
cooperation with other state agencies including DelDOT, the Department of Natural Resources
and Environmental Control (DNREC), Department of Agriculture, and State Housing Authority.
The document represented the state’s first attempt to review the comprehensive planning efforts
statewide, synthesize them, and resolve discrepancies. The document and corresponding map
were primarily shaped by plans adopted by the counties, two metropolitan planning
organizations, and state agencies. At the time, few of the state’s municipalities had updated
comprehensive plans.
Building on a strategy developed by WILMAPCO in 1996, the state was categorized into three
primary land development and investment strategies and four subcategories. The strategy map
for New Castle County can be found in Appendix E. The primary strategies include:
• Communities, including the subcategories of Urban Centers and Employment Centers
• Developing Areas and the subcategory of Secondary Developing Areas
• Rural Areas
• Environmentally Sensitive Areas, which are only present in Sussex County
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
43
In general, the state strategy document defines a Community as a population center with
traditional, compact development. Most of the state’s municipalities are considered
Communities. Developing Areas tend to be suburban or suburbanizing, lower-density areas.
Rural Areas are predominantly agricultural. The plans developed by WILMAPCO, New Castle
County, and DelDOT reflect the basic strategy, which is explained outlined below within the
context of transportation:
• Communities: areas where population is concentrated, commerce is bustling, and a wide
range of housing types exist. State policies encourage redevelopment and reinvestment.
“In communities, the state will provide the greatest number of transportation options with
an emphasis on public transportation, walking, and bicycling. It will also make existing
infrastructure and planned improvements as safe and efficient as possible. Typical
transportation projects will include new or expanded facilities and services for all modes
of transportation, including public transportation facilities and services when favorable
development patterns and densities exist. Projects will also include those that manage
traffic flow and congestion, support economic development and redevelopment efforts,
and promote local street networks.”
• Developing Areas: areas where state investments and policies will be targeted to
accommodate existing development and orderly growth. “In developing areas, the state
will encourage sensible development through a planned set of phased transportation
investments, land use coordination, and policy actions consistent with zoning densities
and designations. A minimum net density of four units per acre will be used as a
guideline in making transportation investments. Transportation projects in developing
areas will typically expand or provide roadways, public transportation, pedestrian
walkways, bicycle paths, and other transportation modes. Projects will also include those
that manage traffic flow and congestion, support economic development and
redevelopment efforts, and promote local street networks.”
• Rural Areas: state policies will encourage the preservation of a rural lifestyle and
discourage new development. “In rural areas, the state will preserve existing
transportation facilities and services and manage the transportation system to support the
preservation of the natural environment. Transportation projects will include only
necessary drainage, maintenance, and safety improvements and programs to efficiently
manage regional highway facilities.”
Currently, the state strategies document is being updated to reflect recently revised county and
municipal comprehensive plans that have been developed since the strategies were first adopted.
Currently, the Office of State Planning Coordination is working with a consultant to develop a
guidebook for Delaware municipalities, helping them make better land use and planning
decisions. The book will present guidelines, ideas, and resources that towns can use to develop
comprehensive plans, update zoning and subdivision codes, and review development proposals.
The guidelines in the book will reflect many of the national recommendations summarized below
and are intended to encourage development that is more profitable, attractive, convenient, and
environmentally sensitive than conventional auto-oriented development. The guidebook is
scheduled to be available in 2004.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
44
Research and Recommendations
In response to the policy documents, studies were conducted to determine the best techniques for
implementation. The studies made recommendations for improving land use and transportation
planning in New Castle County and the state. The following section of the notebook will review
the studies below:
• Churchmans Crossing Study, 1996
• Transit Overlay Districts and Transit-Friendly Design Standards for New Castle County,
1997
• Mobility Friendly Design Standards, 1997 (WILMAPCO)
• Traditional Neighborhood Development Guidelines, 1997
• Planning Delaware’s School Needs: Issues of Location, Design and Infrastructure, 2001
• Building Quality Schools: Revisions to the School Construction Formula and
Recommendation Standards, 2002
• The Future of School Siting, Design and Construction in Delaware, 2003
Implementation Activities
New Castle County and DelDOT have incorporated some of the recommendations into their
respective codes, regulations, and manuals. The following documents are reviewed in this
section:
• New Castle County Uniform Development Code, 1998 and amendments
• DTC Bus Stop and Passenger Facilities Policy, 2000
• DelDOT Mobility Friendly Design Standards, 2000
• DelDOT Traffic Calming Design Manual, 2000
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
45
B. Mobility Friendly Design
Research and Recommendations
DelDOT initiated the Churchmans Crossing Study in response to growing congestion problems
in suburban employment and retail centers designated as growth areas in New Castle County.
DelDOT created a partnership with WILMAPCO and New Castle County to integrate both
transportation and land use planning issues and solutions. The study utilized computer
transportation modeling to determine the effectiveness of the various transportation measures
evaluated.
Although the recommendations from this study were primarily focused on specific transportation
projects, the following is considered mobility friendly:
“Adopt specific design guidelines for the following types of land uses: residential, office
employment, regional commercial, sports/entertainment, and institutional as well as open
space.”
In 1997, WILMAPCO, DelDOT and the Town of Middletown collaborated on the Mobility
Friendly Design Standards study. The purpose of the study was to develop coordinated land use
and transportation recommendations for enhanced mobility. In addition to basic
recommendations, the document includes specific changes to DelDOT’s Rules and Regulations
for Subdivision Streets and Middletown’s Subdivision Code and Zoning Code, many of which
are applicable countywide. Land use recommendations include:
• Allow mixed-uses by 1) allowing neighborhood commercial uses in or near residential
districts as a conditional use; 2) allowing all types of residential uses within the
commercial district, including apartments over stores and offices; 3) allowing retail uses
within the office/employment zones; and 4) allowing incidental service and retail uses
(maximum ten percent of building area) within the manufacturing/industrial district.
• Reduce building setbacks and increase parking setbacks to shorten walking distances and
improve the pedestrian experience: 1) set back attached residential garages at least 20
feet from the street; house facades require a setback of ten feet; 2) reduce rear and side
yard setbacks for detached residential garages (served by alleys) to five feet to be served
by alleys; 3) reduce commercial setbacks to ten feet to bring buildings closer to the street;
and 4) set back commercial and multi-family residential parking lots at least ten feet from
the property line and screen from view.
• Improve the pedestrian and aesthetic experience through the design and location of
parking lots: 1) locate all non-residential parking lots to the rear and sides of buildings;
2) plan pedestrian walkways to afford direct access to building entrances and transit stops
while minimizing conflict with vehicles; 3) require inter-parcel pedestrian and vehicular
access; 4) provide landscaping to screen the parking lot, minimize the visual impact of
large expanses of asphalt, and create a more pleasant pedestrian experience through and
around the site; 5) reduce the minimum allowable size of parking spaces from 180 to 162
sq ft with a nine-foot width; 6) reduce the minimum number of required commercial
parking spaces to three spaces per 1000 sq ft plus one space for each two employees; and
7) provide one five-space bicycle rack for the first ten automobile spaces, plus an
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
46
•
•
•
•
•
•
additional bike space for each ten additional auto spaces, up to a maximum of 20 bicycle
spaces.
Design the site and internal circulation of shopping and employment centers to allow for
the through movement of transit vehicles and shorten average walking trips (less than 300
feet) from transit stops to building entrances.
Require all new shopping and employment center developments to include public spaces
with amenities, such as seating, lighting, special paving, landscaping, artwork, and
recreational features. Pedestrian walkways and buffer areas are additions to this public
space.
Improve the pedestrian experience through varied non-residential building articulation
and design. To that end, 1) avoid blank walls along streets and sidewalks; 2) divide long
facades into smaller segments with windows, architectural detailing, color, and facade
setbacks; 3) encourage smaller lot sizes, narrower lot widths, and minimum setbacks in
pedestrian areas.
Require all new subdivisions to identify all trip generators within a half-mile radius of the
perimeter of the proposed subdivision on the preliminary plan. In addition, graphic or
written descriptions of all proposed connections between the proposed development and
nearby trip generators shall be required. The submission shall also include the locations
of all existing and proposed bike paths/routes within the proposed development and
within one mile of the development.
Create a street network with the following criteria: 1) new subdivisions should have a
Connectivity Index [the ratio of street links to street nodes (intersections and cul-de-sac
heads)] of at least 1.4; 2) discourage through traffic on local streets and encourage
linkages between neighborhoods, community facilities, and shopping areas; 3) plan
arterial street networks for an average half-mile grid; 4) do not exceed block lengths of
500 feet; 5) permit alleys in residential zones with rights-of-way of 20 feet and minimum
paved widths of 12 feet; and 6) avoid cul-de-sacs as loops are preferred. Where cul-desacs are necessary, do not exceed 500 feet in length, with a preferred length of no more
than 250 feet. Bicycle and pedestrian connections should be provided between cul-desacs, collectors, minor arterials, and other community facilities.
Increase bicycle and pedestrian facilities:
1) Provide sidewalks as part of all new development and redevelopment greater than
one dwelling unit per acre [less than one du/acre: none required, one to two du/acre:
sidewalks required on one side of the street, and cul-de-sacs and greater than two
du/acre: sidewalks required on both sides of the street].
2) Design sidewalks to be a minimum of five feet where a greenstrip is provided
between the curb and the sidewalk and a minimum of eight feet where there is no
greenstrip. Greenstrips shall be a minimum of five feet wide. The greenstrip should
be a minimum of ten feet wide where residential units front collector streets.
3) Provide pedestrian ways internal to a site, linking parking areas and building
entrances as well as between building entrances.
4) Provisions should be made by developers for bicyclists along collector and arterial
streets according to DelDOT standards, connecting with existing or proposed bicycle
facilities within one mile of the proposed development.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
47
•
•
Require landscaping:
1) Provide street trees at one tree per 40 linear feet of right-of-way frontage, located
within the greenstrip. Alternate location is behind the right-of-way, no closer than
three feet to the sidewalk.
2) Locate landscaping, walls, and fencing to preclude site-to-site connections.
Require open space: at least 50 percent of required open space should be useable, visible,
and accessible to residents within a community.
Recommendations made by WILMAPCO’s Mobility Friendly Design Study for minor streets and
minor collector streets include:
• Create internal circulation systems that consist of short, interconnected streets, achieving
a Connectivity Index of at least 1.4. Loops are preferred to cul-de-sacs, block lengths not
to exceed 500 feet.
• Lower design speeds to 20 mph for minor streets and to 25 mph for minor collector
streets. Post these as the operating speeds. Existing roadways with higher design speeds
are not eligible for lower speed postings. With lower design speeds, the horizontal curve
radius can be reduced to correspond to new design speeds.
• Encourage T- and four-way intersections. Roundabouts are preferred to stop signs, where
applicable. Intersections shall occur at 90-degree angles, with a minimum of 60 degrees
allowed on local streets. Allow L-curves or 90-degree turns in loop or U-shaped
roadways.
• Reduce minimum curb return radii to reduce crossing distances for pedestrians and slow
vehicles. Note that school bus routes need to be planned and designated as part of the
following street network:
o Minor street-to-minor street curb return radii:
10 feet
o Minor street-to-collector with parking lanes:
15 feet
o Collector streets-to-collector with parking lanes:
20 feet
o Minor street-to-collector without parking lanes:
40 feet
o Collector street-to-collector without parking lanes: 40 feet
• Discourage the use of cul-de-sacs. Where necessary, the preferred maximum length is
250 feet, not to exceed 500 feet. Provide pedestrian connections between cul-de-sac
heads and other adjacent streets.
• Allow alleys in residential zones with a right-of-way width of 20 feet and minimum
paved width of 12 feet.
• Allow driveways at 50-foot minimum spacing from centerlines. Narrower lots shall
require alley access or shared driveways. Driveways shall be staggered so that they do
not line up across from one another.
• Allow reduced lane widths: nine-foot travel lanes on minor streets and ten-foot travel
lanes on minor collectors. Striped parking lanes should be seven feet wide. With a onefoot offset on each lane, minor roads can have a pavement width of 20 to 27 feet,
depending, on whether or not a parking lane is provided. Minor collectors can have a
pavement width of 29 to 36 feet, depending on whether a parking lane is provided on one
or both sides.
• Provide sidewalks as part of all new development and redevelopment greater than one
dwelling unit per acre [less than one du/acre: none required, one to two du/acre:
sidewalks required on one side of the street, and cul-de-sacs and greater than two du/acre:
Mobility Friendly Design Standards: A Framework for Delaware
48
DRAFT: February 2004
•
•
sidewalks required on both sides of the street]. Sidewalks should be a minimum of five
feet wide where a greenstrip is provided between the curb and the sidewalk, and a
minimum of eight feet wide where there is no greenstrip. Greenstrips shall be a
minimum of five feet wide. The green strip should be a minimum of ten feet wide where
residential units front collector streets.
Provide street trees at one tree per 40 linear feet of right-of-way frontage, located within
the greenstrip. An alternate location is behind the right-of-way, no closer than three feet
to the sidewalk.
Provide bicycle facilities according to Federal Highway Administration guidelines.
Conducted jointly by New Castle County and DelDOT in 1997, the Traditional Neighborhood
Development (TND) Guidelines study was an outcome of the Churchmans Crossing Study,
which was intended to assist in the development of the New Castle County Unified Development
Code (UDC). The recommendations were proposed as an alternative to traditional suburban
development patterns, by channeling growth into higher-density, mixed-use development
patterns that promote walking, transit usage, and a sense of community.
This study identified four types of TND development: 1) Rural Hamlet, which would be 20 to
40 acres in size and intended for the preservation of rural open space; 2) Neighborhood, which
would be 20 to 120 acres and would most likely occur as an infill development in an
urban/suburban area; 3) Village, which would be 200 to 600 acres and would likely consist of
several neighborhoods oriented toward some common public/civic uses and limited retail and
office uses. Villages are intended as alternatives to large suburban developments. 4) Town,
which would range from 1500 to 3000 acres and function as an independent, distinct community.
General TND design guidelines include:
• Require all buildings, both residential and non-residential, to be oriented toward (facing)
pedestrian-scaled public streets or spaces.
• Locate similar building types and intensities on both sides of the street to establish a
unified street identity.
• Require commercial build-to lines 15 to 20 feet from the curb. The distance may be
greater in transitional areas oriented to arterial streets.
• Require residential build-to lines 15 to 20 feet from the property line or sidewalk in a new
development. For infill or redevelopment sites, the build-to line should be the same as
surrounding buildings.
• Require development in commercial areas, especially for ground-floor street frontage, to
be varied and articulated and include windows and multiple entrances. Flat, blank walls
are not acceptable.
• Require the primary entrances of buildings to face public streets, plazas, or parks, rather
than interior blocks or parking lots.
• Require residential building facades to be varied with front doors facing and visible from
the street.
• Require the TND street pattern to be interconnected and provide multiple routes to the
TND Center and the surrounding regional system.
• Avoid dead-end streets and cul-de-sacs.
• Design TND road networks to a connectivity index of at least 1.4.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
49
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Encourage alleys in both residential and non-residential areas.
Require curb return radii to be ten feet or less.
Establish a preferred block length of 250 to 500 feet; cul-de-sacs may not exceed 250 to
500 feet, depending on density and topography.
Require TNDs to incorporate a well-defined system of pedestrian routes.
Require residential sidewalks to be at least five feet wide.
Require commercial area sidewalks to be 7.5 to 15 feet wide, depending on the presence
of pedestrian amenities or obstructions.
Institute traffic calming measures as needed.
Require transit stops in TND areas to include benches and shelters.
Reduce residential parking requirements by granting credit for on-street spaces on a onefor-one basis for up to half of the required spaces. The credit should be limited to the
number of spaces along the street frontage immediately adjacent to the project.
Revise commercial/office parking requirements to allow a higher percentage of spaces to
be smaller and designated for compact cars (40 to 60 percent). Reduce the total number
of required spaces in mixed-use projects, recognizing trip-combination opportunities (10to 15-percent reduction). Reduce the number of required spaces where adjacent uses can
share or combine parking because of differences in the peak parking demands associated
with different uses, such as an office, entertainment, or church.
Require large surface parking lots to be set back at least ten feet from property lines and
screened with a wall, fence, or year-round landscaping at the street edge.
Require residential parking lots to have one landscaped island per ten parking spaces.
Require commercial/office parking lots to have one landscaped island per 20 parking
spaces.
Locate parking to the side or rear of non-residential buildings.
Locate residential garages to the rear of houses or set back the garage from the primary
residential structure.
Provide bicycle parking. In parking lots with fewer than ten parking spaces, provide a
bicycle rack with at least five spaces. In parking lots with more than ten spaces, provide
five bicycle spaces plus an additional bicycle space for every ten car spaces.
Create zoning categories for each of the TND types and proactively zone accordingly or
allow the four TND categories as a conditional use in other zones.
Recommendations for Rural Villages/Hamlets, in addition to the general recommendations
above, include:
• Allow 20 to 40 acres of development surrounded by preserved rural/agricultural land and
open space.
• Allow 50 to 100 dwelling units, including a variety of housing types and sizes.
• Require land uses to consist of 71- to 75-percent residential, 20-percent minimum open
space, and 5-percent minimum natural open space.
• Permit some additional uses: 0- to 2-percent commercial, 0- to 2-percent employment,
and 0- to 2-percent civic and institutional.
• Require a defined center to be the focal point of the community.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
50
Recommendations for Neighborhoods, in addition to the general recommendations above,
include:
• Allow 20 to 120 acres (one-quarter-mile radius) with a variety of housing types,
including both single- and multi-family housing.
• Require any development greater than 120 acres to be divided into smaller
neighborhoods.
• Required the following land uses: 70- to 85-percent residential, 10-percent minimum
open space, 0- to 5-percent civic and institutional uses.
• Require the focal point to be a park, plaza, or public building near the geographic center.
• Locate higher-density housing closer to the center, with lower-density housing located
towards the perimeter.
• Limit commercial uses to local-scale retail and service uses.
Recommendations for Villages/Towns, in addition to the general recommendations above,
include:
• Require 200 to 3000 acres, consisting of multiple neighborhoods.
• Required the following land uses: 60- to 80-percent residential, 10-percent minimum
public open space, 5-percent minimum natural open space, 2- to 10-percent commercial,
0- to 15-percent employment, and 3-percent civic/institutional uses.
• Require a variety of housing types including both single- and multi-family housing.
• Require a defined center to include mixed-commercial and civic uses. Larger
developments should have more intense civic and employment uses.
• Require high-density housing to be located closer to the center, with low-density housing
towards the perimeter.
• Require some commercial uses to be located in two-story-minimum buildings, with upper
floors containing residential or office uses.
• Allow commercial or employment districts to be located at the periphery of the district
for vehicular accessibility. Orientation, however, should serve both pedestrian and nonresident users.
Implementation of the Recommendations
Some of the recommendations have been implemented, with varying degrees of success. Here
are examples of how the recommendations have been adopted in Delaware.
The Mobility Friendly Design Standards, adopted by DelDOT in 2000, provide an alternative
way to design local and minor collector subdivision streets. The standards outlined below are
optional, but must be applied in their entirety. Additionally, it was intended that the standards be
automatically permitted within the WILMAPCO Multimodal Investment Area (roughly
equivalent to the state’s Community, Developing, and Urban Areas), but the standards would
have to be considered individually as to their application in the WILMAPCO Management and
Preservation Areas (roughly equivalent to the state's Secondary Developing and Rural Areas.
The standards are divided between Local Subdivision Streets and Minor Collector Subdivision
Streets. As of the date of this publication, no developer has elected to use the standards in
Delaware.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
51
Mobility Friendly Local Subdivision Street Standards:
• Require a minimum connectivity index of 1.4.
• Encourage 200- to 500-foot preferred block lengths, with mid-block pass-throughs and
crosswalks where blocks greater than 500 feet are needed.
• Design streets for 20 mph travel, instead of 25 mph.
• Use T- or four-way intersections as much as possible.
• Prohibit all-way stops as a method of speed control at low-volume intersections.
• Reduce the minimum corner radius between two local subdivision streets to 25 feet;
between local and collector subdivision streets with parking to 30 feet; and between local
and collector subdivision streets without parking to 40 feet.
• Limit cul-de-sac lengths to a 300-foot maximum, serving no more than 30 units and with
cut-throughs at cul-de-sac heads for pedestrians and bicyclists.
• Require 50-foot minimum driveway spacing, with narrower lots requiring alley access or
shared driveways.
• Reduce the minimum driveway width to 8 to 16 feet for single-family developments,
depending on setback of garage and number of cars; and 18 feet for multi-family
development.
• Allow the minimum right-of-way width required to be 52 feet, based on a 12-foot travel
way, two one-foot curb offsets, one seven-foot parking lane, one six-inch curb on each
side of the street, one ten-foot planting strip on each side, and one five-foot sidewalk on
each side of the street. Pavement width should be 21 feet.
• Encourage medians or islands on all multi-lane roads with additional right-of-way
required to accommodate them.
• Reduce the minimum horizontal curve radius to 167 feet when the curve is unsigned or
90 feet when signed as a traffic calming device (versus 300 feet).
• Require five-foot minimum sidewalks on both sides of the street.
• Require ten-foot minimum planting/buffer/utility strip.
• Provide at least three-foot minimum tree/obstacle clearance with a vertical curb as
measured from the back of curb to the centerline of the tree.
• Recommend alleys when lots are less than 50 feet wide. When an alley is provided, a 20foot right-of-way is required with a 12-foot pavement width.
• Require a full array of horizontal and vertical traffic calming measures consistent with 25
mph design speeds, except on emergency response routes.
Mobility Friendly Minor Collector Subdivision Street Standards:
• Require a minimum connectivity index of 1.4.
• Encourage 200- to 500-foot block lengths, with mid-block pass-throughs and crosswalks
when blocks are greater than 500 feet.
• Design streets for 25 mph travel instead of 30 mph.
• Encourage roundabouts and two-way stops instead of traffic signals.
• Discourage unwarranted stop signs, except when an engineering study shows unusually
high cut-through volumes or an unusually high accident rate.
• Reduce minimum corner radius between local and collector subdivision streets with
parking to 30 feet and between local and collector subdivision streets without parking to
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
52
•
•
•
•
•
•
•
•
•
•
40 feet. Collector-to-collector subdivision streets with parking should have minimum
corner radius reduced to 25 feet and collector-to-collector subdivision streets without
parking to 50 feet.
Limit cul-de-sac lengths to 300-foot maximum, serving no more than 30 units, and with
cut-throughs at cul-de-sac heads for pedestrians and bicyclists (versus 500 to 1000 feet).
Allow 50-foot minimum driveway spacing, with narrower lots requiring alley access or
shared driveways (versus 200 feet).
Reduce minimum driveway widths to 8 to 16 feet for single-family developments and 18
feet for multi-family developments.
Allow the minimum right-of-way width required to be 53 feet to a 60-foot maximum,
based on two ten-foot travel lanes, two one-foot curb offsets, one seven-foot parking lane,
one six-inch curb on each side of the street, one ten-foot planting strip on each side, and
one five-foot sidewalk on each side of the street. The minimum right-of-way can be used
if on-street parking is eliminated. Pavement width required is 22-foot minimum to 29foot maximum.
Allow a 90-foot minimum horizontal curve radius when the curve is unsigned or 45-foot
minimum radius when signed as a traffic calming device (versus 150 feet).
Require five-foot minimum sidewalks on both sides of the street.
Require five-foot minimum planting/buffer/utility strip.
Require at least three-foot minimum tree/obstacle clearance with a vertical curb as
measured from the back of the curb to the centerline of the tree.
Recommend alleys when lots are less than 50 feet wide. When an alley is provided, a 20foot right-of-way is required with a 12-foot pavement width.
Allow a full array of horizontal and vertical traffic calming measures consistent with a 20
mph design speed.
The New Castle County Uniform Development Code (UDC), adopted by the New Castle County
Council in 1998 with subsequent revisions, has provisions relating to the design of the
transportation system including streets, sidewalks, and parking lots. Also, the UDC includes
some special design types that were developed in response to transportation issues. The designs
include mixed-use districts, traditional neighborhood design, Villages, and Hamlets. In addition,
the UDC allows density bonuses for infill projects close to a transit stop, which is discussed in
the next section entitled “Transit.” The code provisions in the Uniform Development Code
relating to mobility friendly design follow:
• Section 20.110 E. “All street and circulation patterns shall provide for the safe, efficient,
and convenient movement of vehicular and pedestrian traffic. Vehicular travel lanes,
pedestrian movement systems, and parking should be separated. Within the context of
overall community development, the internal circulation system should promote and
encourage the increased use of pedestrian and bicycle movement among residential, local
shopping, schools, and other areas. Road connections shall seek to avoid external
automobile trips through the employment of superblocks, stub streets, connecting open
space, bicycle-pedestrian ways, and other design techniques and devices.”
• Section 20.210 A. Blocks should not generally exceed 15 lots in length [at 85-foot
minimum width = 1275-foot block].
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
53
•
•
•
•
•
•
•
•
•
•
•
•
•
Section 20.230 J. Cul-de-sacs shall not serve more than 16 lots except (680 to 1360 feet)
where topography, open space or resource protection dictates. Lengths of six to fourteen
lots [510 to 1190 feet] are preferred.
Section 20.230 I. Alleys are only allowed in the TN district and in Hamlets and Villages.
Where allowed, they must be at least 20 feet wide, with paving at least 15 feet wide.
Garages accessing the alley shall be set back at least 18 feet from the alley right-of-way.
[See also Section 03.410: garages facing an alley must be set back at least 20 feet; and
Table 10.210, which stipulates a minimum five-foot setback from the rear property line
for garages in Villages with access to an alley].
Section 21.130 C. Subdivisions or developments of 300 or more dwelling units must be
served by at least two entrance streets located as far apart as possible from each other.
Section 21.131 A. Residential subdivisions and developments shall have an internal
street or accessway system capable of accommodating school bus traffic. To facilitate
this, the vehicular circulation pattern shall incorporate a system of circular or loop streets.
This system must not necessitate the school bus to back up.
Section 23.151 Street trees are required in new development, on both sides of the rightof-way at a rate of one tree per 40 feet.
Section 21.162 Sidewalks are required on both sides of the street for new development,
except when residential lots are one acre or larger where none are generally required.
New Castle County’s Department of Land Use reserves the right to require sidewalks
anyway for safety reasons.
Section 21.163 Sidewalks shall be at least five feet wide with a minimum five-foot
planting strip between the back of curb and sidewalk.
Section 22.611 E. All parking areas shall provide attractive, direct, and safe pedestrian
access to all parking spaces, and protected from vehicular encroachment.
Section 22.611 K. Parking spaces for separate buildings or uses may be combined in a
single parking lot, provided that the total number of spaces shall be greater than or equal
to the sum of spaces required for each individual use.
Section 22.611 M. Bicycle parking must be located to be highly visible from the street
or main building entrance, and separated from motor vehicles.
Section 03.527 Parking facilities containing more than ten parking spaces shall provide
one bicycle space or locker for each ten vehicular spaces up to a maximum of 20 bicycle
spaces or lockers.
Section 22.611 N. Parking lots with at least 200 spaces may dedicate up to five percent
of the spaces to use as a park-and-ride facility in connection with public transportation.
Section 22.616 Parking reductions are allowed where a land use or building is occupied
by uses with different peak parking needs. However, the development shall contain
sufficient open space to accommodate the parking spaces that are not built.
Mixed-uses are allowed in the following zoning districts: Suburban (S), Traditional
Neighborhood (TN), Commercial Neighborhood (CN), Commercial Residential (CR), Office
Neighborhood (ON), and Office Regional (OR).
• Section 03.318 A mixed-use district shall include a minimum of five dwelling units
comprising 25 to 50 percent of the total gross floor area on the site. At least three
additional uses must be on the site (commercial retail and service, restaurant, office,
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
54
•
neighborhood institution, or public service). Gas stations, single-use restaurants, or
drive-throughs are not permitted in a mixed-use district. In the OR and ON districts, at
least 67 percent of the non-residential gross floor area of the development must consist of
office uses.
Section 07.620 Provides a mixed-use bonus to encourage infill development. This bonus
has never been used.
Traditional Neighborhood Design is only allowed in the TN district. There is currently no land
zoned TN in New Castle County.
• Section 25.230 Traditional Neighborhood Design is intended to provide the character of
an urban neighborhood having formal open spaces serving as neighborhood focal points.
The site should be developed using a grid or other formal pattern with vehicular access to
units via alleys.
• Section 20.210 D. A grid or other formal system is desired in which open spaces are
integrated into the block design Alleys are considered desirable for the areas where lot
sizes are less than 20,000 square feet.
Hamlets and Villages
• Section 20.210 D. A grid or other formal system is desired in which open spaces are
integrated into the block design Alleys are considered desirable for the areas where lot
sizes are less than 20,000 square feet.
• Section 25.130 Hamlets and Villages shall be divided into two major areas: rural open
space and the development area, which contains commercial, residential, community
open space, and employment areas.
• Section 25.131 Residential areas of Hamlets and Villages are intended to include various
types of single-family detached dwellings. Multi-family dwellings are permitted but
primarily to be located within mixed-use structures or commercial apartments. Higher
levels of multi-family development may be allowed with higher levels of employment.
• Design guidelines must be established for the Hamlet or Village to present traditional
facades and screen traffic, as well as for specific uses.
• Section 07.330 Density bonuses are available in Hamlets and Villages.
• On-street parking may be counted towards required parking in Hamlets and Villages.
Hamlets are allowed in the S and Suburban Reserve (SR) districts. Since the adoption of the
UDC, no Hamlets have been proposed.
• Hamlets should be a minimum of 600 acres with 900 to 1200 dwelling units, with 10 to
20 percent maximum multi-family and attached single-family dwellings.
• Commercial uses shall be in the Hamlet center and be limited to neighborhood retail,
office, restaurants, service businesses, bed and breakfasts, and home businesses.
Villages are only allowed in the S district. Since the adoption of the UDC, no Villages have
been proposed.
• Villages should be a minimum of 1000 acres with 1800 to 2200 dwelling units, with 20to 45-percent maximum multi-family and attached single-family. Villages are required to
have an area for employment uses.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
55
•
Commercial uses and home businesses shall be in the Village center and limited to
commercial retail, office home furnishings and appliances, services, commercial lodging,
restaurants, bed and breakfasts, and home businesses. Light auto is permitted with some
restrictions. More commercial uses are allowed in the Village than in the Hamlet.
Table 8: Maximum Residential Densities, Suburban Districts (UDC Table 07.221)
Development Type
Max. Gross Density Max. Net Density
SR - Open Space Subdivision
S - Open Space Planned
0.43
1.86
0.80
5.00
S - Hamlet
2.10
5.60
S - Village
2.15
6.00
S - Village with bonus
2.25
6.50
Other Mobility Friendly Initiatives Underway
DelDOT last updated the Standards and Regulations for Subdivision Streets and Highway Access
transportation manual in 1984. DelDOT has begun to update this manual to reflect current issues
and conditions, including the studies and reports outlined above. In addition to basic design and
construction information, the updated manual will include specific information related to the
geometric design of subdivision streets, an interconnectivity policy, sidewalk/bicycle policy, and
landscaping policy, incorporating the mobility friendly design standards.
Recently, DelDOT has started to develop a pedestrian plan for Delaware. This plan will develop
a vision for pedestrian facilities within the right-of-way, along with goals and objectives.
Ultimately, the purpose is to guide the provision of pedestrian facilities along state roadways and
establish guidelines and priority areas. The plan is expected to be finalized in summer of 2004.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
56
C. Transit
Research and Recommendations
The Churchmans Crossing Study (DelDOT, WILMAPCO, and New Castle County) produced
the following recommendations related to transit:
• Create a new zoning classification, Transit Overlay District, to include interconnected
street and sidewalk systems, appropriate mixed land uses, and transit supportive densities,
where higher levels of transit service are to be provided.
• Adopt design guidelines for the Transit Overlay District for use in the vicinity of the
proposed commuter rail station.
• Improve transit supportive pedestrian facilities. Provide sidewalks that connect bus stops
to homes, workplaces, and shopping. Provide crosswalks and pedestrian signals at all
major intersections along with bus stop pads with curb cuts at all stop locations; benches
and shelters at stops with significant boardings; and lighting and landscaping along
pedestrian paths and at bus stops.
In addition to the land use and street design recommendations previously outlined,
WILMAPCO’s Mobility Friendly Design Standards study made specific recommendations for
transit facilities and enhanced transit accessibility.
• Bus stops are required to provide a safe place to stand and wait. A five-foot sidewalk is
required on both sides of the street. Shelters and benches should be encouraged and,
where provided, must not reduce the clear width of the sidewalk to less than 36 inches.
• Bus stops located in areas without sidewalks require a sidewalk pad, with a minimum
width of five feet and a minimum length of 12 feet.
• Sidewalks at bus stops should extend to the street curb. Grassed or landscaped strips
may not be located between sidewalk and curb.
• Bus stops should be located adjacent to signalized intersections, where crosswalks can
provide safe pedestrian crossings. A safe means of crossing the street must be provided
in close proximity to the bus stop where there are major generating uses located at some
distance from a signalized intersection,.
• Bus stops are required to be lighted and are required to provide a bus stop marker with
bus schedule display.
• Intersections within one-quarter-mile of a bus stop are required to have marked
crosswalks.
• Bus pull-out bays may be used if sufficient shoulder width does not exist for buses to
pull out of the travel lane at bus stops. Bus pull-out bays, however, should only be used
where sufficient right-of-way exists to construct them and where warranted by traffic
volumes and travel speeds. In most instances, bus pull-out bays are unnecessary on
minor streets and minor collector streets, given the traffic volumes and travel speeds.
• Park-and-ride lots should be designed with attention to pedestrian safety and amenities.
Park-and-ride lots should contain shelters, benches, bicycle parking and storage
facilities, pedestrian-scale lighting, and kiosks.
The Review of Transit Oriented Development and Transit Overlay Districts (Vanasse Hangen
Brustlin, Inc.), sponsored by DelDOT and managed by New Castle County, was completed in
1997. The review focused on national transit-related literature that was considered to be relevant
Mobility Friendly Design Standards: A Framework for Delaware
57
DRAFT: February 2004
to the county. The review points out that the majority of transit-oriented activities have been
developed in conjunction with rail transportation, and only occasionally with major bus hubs. It
was the background paper for the report, Transit Overlay Districts and Transit Friendly Design
Standards for New Castle County (Vanasse Hangen Brustlin, Inc.), which is highlighted below.
Transit Overlay Districts and Transit Friendly Design Standards for New Castle County was,
also, sponsored by DelDOT and managed by New Castle County. Completed in 1997, the report
translates the best practices and key elements outlined in the previous report into recommended
standards for the county. The following three-tiered approach to transit-oriented standards was
recommended: 1) General standards that support basic walking and bicycling mobility would be
applicable anywhere there is an existing or planned residential density of at least two dwelling
units per acre. 2) Transit Arterial District Standards would be used within one-quarter-mile of a
transit-served corridor to promote, rather than simply accommodate, transit usage. 3) Activity
Center District Standards would be applicable where there is access to multiple transit lines,
including a mix of land uses, and at least two of the following minimums:
• 150,000 sq ft of retail use
• 100,000 sq ft of office use
• 100 dwelling units at a minimum density of approximately five units/acre
• Civic or institutional uses such as a post office, school, library, or health care facility
General Standards (two or more du/acre) include:
• Short interconnected streets, direct routes, and loops are preferred to cul-de-sacs on local
streets. T- and four-way intersections with two- and four-way stop control or
roundabouts are preferred, with marked crosswalks.
• Block lengths of 200 to 500 feet are preferred. Longer blocks require mid-block
crosswalks and pedestrian pass-throughs.
• Lengths of 250 feet are preferred for cul-de-sacs, with a maximum of 500 feet or no more
than 30 dwelling units, with a bike/pedestrian cut-through at the head.
• Minimum driveway spacing should be 50 feet, with smaller lots requiring alley access or
shared driveways. Maximum driveway width should be 8 to 16 feet for single-family or
18 feet for multi-family dwellings. Stagger driveways by alternating with on-street
parking.
• Subdivision or land development submittals should include a pedestrian- and bicyclecirculation plan showing the location of all walkways and bike paths and how they
connect to adjacent parcels, nearby transit facilities, and the surrounding street system.
• Continuous systems of paved walkways will be required for all parcels to provide
circulation: 1) within the parcel, 2) between the parcel and adjacent streets, 3) between
the parcel and any nearby transit facilities, or 4) between the parcel and adjacent land
uses.
• Sidewalks on both sides of the streets are required in areas with two or more du/acre;
sidewalk on one side is required at one to two du/acre, none are required at less than one
du/acre. Sidewalks are required on both sides of cul-de-sacs. Minimum sidewalk width:
five feet with buffer strip, eight feet without. Vertical clearance must be eight-foot
minimum.
• Bicycles should be accommodated on the street.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
58
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Buffer/planting strips should be five-foot minimum; zero feet permitted for commercial
uses with eight-foot minimum sidewalks. Tree/obstacle clearance is 2.5 feet from the
back of the curb to the centerline of tree, with one tree per 40 linear feet of right-of-way.
Clearly marked, paved walkways must be provided where pedestrians are required to
cross through parking lots, and to connect public sidewalks and bus stops to building
entrances. A five-foot minimum clear width must be maintained with landscaping or
parking bumpers, etc.
Walkways between non-residential parcels should be protected with a pedestrian
easement (minimum of 15 feet, 20 feet preferred).
Walkways should be lighted if any area or corridor to which they connect is lighted.
Open space should be located as much as possible to integrate with adjoining open space
to create pedestrian interconnection. Do not allow open space to become a barrier to
connection.
On-street parking should be allowed on Access Level four, five, and six roadways [local
streets, collector streets and transit arterials, respectively]. Increase the width of the
bicycle lane from three to four feet where bicycle lanes are present parallel to on-street
parking.
On-street parking that abuts a parcel should be allowed to be counted towards parking
requirements.
Visible, secure bicycle racks should be provided near building entrances in all nonresidential and multi-family development and protected from the weather wherever
possible. Where fewer than ten vehicular spaces are planned, provide at least five bicycle
spaces are required; where greater than ten, provide five spaces plus one for each
additional ten vehicular spaces provided.
Residential parking lot landscaping: one tree and one landscaped island (minimum 9 X
18 feet) for every ten spaces. Non-residential: one tree and one landscaped island
(minimum 9 X 8 feet) for every 20 spaces.
Parking lots should be screened along the street edge and adjacent to abutting uses with a
wall, fence, or landscaping that will provide a year-round visual buffer. Screening must
not exceed three feet in height, when adjacent to a sidewalk, for public safety reasons.
Bus stops, at a minimum, must be lighted, have a sign with the schedule, and provide a
concrete pad. A five-foot sidewalk is required and the clear width with amenities must
not be less than 36 inches under ADA. Encourage developers to provide additional
transit amenities such as shelters, benches, and trash cans where transit service exists or is
proposed.
Sidewalk pads are required to be a minimum 5 X 12 feet where bus stops are required in
areas without sidewalks. Sidewalk pads must extend to the curb, with no grass or
landscape strip between the pad and bus.
Bus stops should be located adjacent to signalized intersections, where crosswalks can
provide for safe crossings. Where there are major trip generating uses some distance
from a signalized intersection, a safe means of crossing the street must be provided in
close proximity to the stop.
Some appropriate dimensional standards:
o Front setbacks: 25 feet for high-density residential (HDR), 40 feet for retail/office
o Height: 35 to 45 feet for HDR, 35 to 55 feet for R/O
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
59
o
o
o
o
o
Rear setback: 35 to 40 feet for HDR, 25 to 40 feet for R/O
Side yard: 14 to 25 feet for HDR, 0 to 35 feet for R/O, 20 feet for mixed-use
Open Space: 25 to 50 percent
Minimum Parking: 1.5-2/du for HDR, 1/200 sq ft for retail, 1/300 sq ft for office
Parking setbacks from lot line: 15 feet for HDR and 25 feet for R/O
Transit Arterial District Standards (to depth of 1/4 mile from the transit arterial) include:
• Allow a mix of uses within zoning classifications.
• Incorporate transportation-based incentives into the review and approval process.
• Designate undeveloped or redevelopment parcels in Transit Arterial Districts as receiving
zones for the Transfer of Development Rights.
• Allow up to 50 percent (at least two acres) of a parcel zoned for non-residential use to be
used for multi-family residential development at seven to ten du/acre. Higher densities
may be considered through the rezoning process.
• Allow residential uses on upper floors of office and retail uses and in close proximity to
retail, office, institutional, and civic uses to encourage vertical and horizontal mixing of
uses.
• Zone undeveloped residential parcels for multi-family residential development at seven to
ten dwelling units per acre and allow auxiliary residential units, such as granny flats,
garage apartments, etc.
• Designate undeveloped parcels or redevelopment parcels within this zone as receiving
zones for the transfer of development rights for other parts of the county.
• Recognize Transit Arterial Districts with zoning or an overlay district.
• Require buildings to address the street and sidewalk with entrances, balconies, porches,
architectural features, and activity areas.
• Require building intensities, orientations, and massing to promote more active
commercial centers, support transit, and reinforce public open spaces.
• Encourage variation in human-scaled detail and architecture [on both residential and nonresidential uses].
• Require a landscape buffer where commercial development abuts residentially zoned land
(minimum five feet). Plantings must be selected to establish an opaque barrier, which
reach a minimum of five feet tall at maturity. In addition, trees must be planted on the
commercial lot to provide screening for upper floors within the residential property.
• Allow reductions in parking where developers can document it would not result in
spillover to adjacent neighborhoods. Grant reductions of up to 20 percent (from base
requirements). Reductions would be based on reduced demand due to pedestrian and
transit access, special use characteristics, and increased use of shared parking.
• Eliminate the existing set-aside provision for shared parking.
• Require parking to be located to the rear or side of the building wherever appropriate.
• Consider how individual sites are designed to prevent locked front building entrances for
pedestrians and transit users as a result of all real access occurring from rear parking lots.
• Accommodate bicycles on-street, either in designated bike lanes, four-foot minimum
paved shoulders, or off-road facilities.
• Avoid large surface lots for park-and-ride facilities, which are auto-oriented, rather than
pedestrian-oriented, within Transit Arterial Districts and Centers. Instead utilize existing
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
60
•
•
•
•
•
•
excess parking, smaller lots, or structured parking. Locate park-and-ride lots close to
ancillary uses, such as convenience stores, dry cleaners, child care, etc. Park-and-ride
lots should be designed to the same standards as other parking lots with landscaping,
crosswalks, screening, etc.
Require all bus stops in the district to have shade trees.
Require all bus stops in close proximity to major residential, retail, or office development
to have a bus shelter.
Require all bus transfer stops and major bus hubs to include enhanced amenities for bus
riders and pedestrians. Shelters must be architecturally distinctive, and must include
benches and kiosks with travel information, such as bus schedules, fares, and ticket
purchasing information. Bus transfer stops and major bus hubs must also include
enhanced landscaping and pedestrian-scale lighting.
Encourage the inclusion of ancillary land uses at major bus hubs for the convenience of
transit users such as newspaper stands, coffee shops, bakeries, sandwich shops, and dry
cleaners.
Some appropriate dimensional standards:
o Front setbacks: 20 feet for high density residential (HDR), ten feet for
retail/office
o Height: 35 to 45 feet for HDR, 40 to 55 feet for R/O
o Rear setback: 20 to 40 feet for HDR and R/O
o Side yard: 14 to 25 feet for HDR, 0 to 35 feet for R/O, 14 to 25 feet for mixeduse residential, 0 to 35 feet for mixed-use office
o Open space: 30 percent for HDR, 20 percent for R/O
o Minimum parking: 1.5/du for HDR, 1/300 sq ft for R/O
o Parking setbacks from lot line: ten feet for HDR and R/O
General transit-oriented densities:
o Residential: seven du/acre are needed to support bus service every 30 minutes
[current DART service], 30 du/acre support ten-minute headways.
o Employment: 50-60 employees/acre where total base employment is 10,000 or
more supports 30 minute headways; Floor Area Ratio greater than two supports
ten-minute headways.
Activity Center Districts:
It was recommended in Traditional Neighborhood Development (TND) Guidelines (LDR
International) that Activity Center Districts undergo additional agency review and establish
individual plans and standards specific to each district because each would be distinct. Activity
Center District standards would be applicable where there is access to multiple transit lines, a
mix of land uses, and at least two of the following minimums:
• 150,000 sq ft of retail use
• 100,000 sq ft of office use
• 100 dwelling units at a minimum density of approximately five du/acre
• Civic or institutional uses, such as a post office, school, library, or health care facility
In addition to the standards listed for other districts, Activity Center Districts should meet the
following land use and density standards:
• Identify appropriate locations for the districts and zone accordingly.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
61
•
•
•
•
•
•
•
•
Incorporate transportation-based incentives into the review and approval process.
Include a full mix of land uses within the districts, such as residential, retail, office, and
other employment and public uses.
Require districts to be at least 30 acres with no maximum size focused around a walkable
core area. To be walkable, the core area should not be greater than 500 acres.
Include high-intensity uses in the Core area, such as residential, retail, or office with high
trip generating characteristics. A secondary area would have lower-intensity uses, but of
greater intensity than the land uses outside the Activity Center District.
Encourage reuse and redevelopment of existing properties.
Encourage at least five percent of the total land area to be dedicated to civic/public open
space.
Indicate the location of transit service and transit amenities on Activity Center District
plans, including a phasing plan for future transit improvements.
Allow park-and-ride lots to be provided within the districts if situated in a manner to
enhance transit access without diminishing the pedestrian environment, or located in
structured parking garages.
Implementation Activities
The DTC Bus Stop and Passenger Facilities Policy was developed in 1999 by the Delaware
Transit Corporation, a division of DelDOT, and became effective April 2000. It was developed
in response to the above studies, as well as the Americans with Disabilities Act (ADA). DTC
guidelines for bus stop spacing were based on a combination of factors that influence the
likelihood of transit usage. DTC used geographic information systems (GIS) to analyze and
categorize areas as high-, moderate-, or low-transit density. Typically, an area will have hightransit density if it is primarily commercial, has a high concentration of employment, or has a
population density greater than 3,000 people per square mile. Areas of moderate-transit density
typically have population densities between 900 and 3,000 people per square mile. Low-transit
density generally occurs in areas where the population density is less than 900 people per square
mile. The requirements for bus stops include:
• Bus stops will be located generally at or near major trip generators, destinations, or at
regular intervals based on the population density and transit-related demographic factors
along the route. Whenever possible, stops in opposite directions on a route will be
located directly opposite each other. Bus stops shall not obstruct driveways or entrance
ways or cause visual obstructions for motorists or bus operators merging back into the
traffic stream. Stops will be placed where they present the least conflict with vehicular
traffic and pedestrians.
• Locations of park-and-ride lots are based on the availability of land, preexisting parking,
or connections to the regional highway system. Park-and-rides may, also, accommodate
carpoolers and bicycle riders and serve as transit hubs. They generally will have a high
level of customer facilities.
• Bus stop interval spacing:
o Local bus service with high transit density: locate stops approximately 750 feet
apart at seven stops per mile, or approximately every three blocks in urban areas.
o Local bus service with moderate transit density: locate stops approximately 1,000
feet apart at five stops per mile.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
62
•
•
o Express and Intercounty Bus Service: stops will generally be located at major
destinations, transfer points, or park-and-ride lots, and may be several miles apart.
o Local and Intercounty Bus Service with low transit density: stop locations will
generally be located based on activity centers rather than distance. In rural areas,
preference may be given to highly visible locations such as commercial areas,
convenience stores, or schools.
o Exceptions may be made for issues such as excessive walking distances,
topographic conditions, demographic characteristics including elderly customers,
and high-volume activity centers.
Pedestrian facilities: DTC does not provide physical improvements outside of the
immediate environment of the bus stop, but will work with appropriate organizations to
provide suitable sidewalks: 36 inches (60 inches preferred) clear width, slope no greater
than 1:12, firm, well-drained surface, ADA and Delaware’s Architectural Accessibility
Board (AAB) compliant curb cuts, and preferably lighted.
Passenger facilities: Facilities are generally provided based on existing or potential
ridership, as physical constraints allow:
o Bus stops are identified by a standard DTC bus stop sign, except where a
jurisdiction provides its own signs.
o Information boards depicting routes and schedules will be provided at major
stops, which generally include stops with shelters or benches and all park-and-ride
locations).
o Bus stops shall have paved passenger waiting areas. At a minimum, a 60-inch
clear sidewalk should be provided. At stops with consistent daily ridership, DTC
may construct a concrete pad measuring at least 8 X 8 feet. All new pads must
meet ADA and AAB standards.
o Benches will be located where the following criteria are met: low-transit density
stops with five or more boardings per day, moderate-transit density stops with ten
or more boardings per day, and high-transit density stops with 20 or more
boardings per day. Benches may also be placed where 1) shelters are allowed but
cannot be installed, 2) there are long intervals between buses, 3) at stops that are
used by a significant number of elderly people, or 4) there have been problems
with passengers sitting on other structures or facilities not associated with the bus
stop.
o Shelters, if they can be safely located, will be installed where the following
criteria are met: low-transit density stops with ten or more boardings per day,
moderate-transit density stops with 20 or more boardings per day, and high-transit
density stops with 40 or more boardings per day. Additional considerations
include passenger transfers, amount and frequency of bus service, elderly
passengers, and proximity to major employment, activity, and commercial
centers. Shelters may be privately provided as long as they meet DTC, ADA, and
AAB guidelines and can be safely located.
o Trash receptacles are generally provided at stops with shelters or benches, highvolume stops, major transfer points, and specific sites where littering has been
identified as a problem.
o All bus stops should be placed in areas where lighting is present or can be
provided. Where lighting is not available, DTC may coordinate with local
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
63
government to provide it for bus stops with night service, high ridership, or
significant numbers of transfers.
o Public telephones will be placed at all park-and-ride locations and at major bus
stops (generally where shelters are located).
o Bicycle-storage facilities will be provided at high-volume locations, park-and-ride
lots, or in other appropriate locations as determined by demand.
Since this policy was adopted in 2000, DTC initiated a review of all transit stops throughout the
state. Of the 2,570 bus stops in Delaware, 42 percent now comply with the policy. In New
Castle County, 834 of 2,043 bus stops, or 40 percent, comply with this policy. The bus stop
improvement program has been suspended temporarily due to lack of staff and the imposition of
a state hiring freeze. The hiring freeze, which had been in effect for 18 months, was recently
lifted.
The UDC, which was adopted in 1998 and subsequently revised, addresses transit in a number of
ways. The TN and Suburban Transition (ST) zoning districts may be located only in areas with
access to transit service (Sections 02.211B and 02.221 D). In the OR and CR districts, transit
facilities are required as part of new development (Sections 02.224 C and 02.225 C).
In the ON, CN, and CR districts (Section 04.110F), the presence of pedestrian facilities or transit
stops can trigger a 15-foot build-to line (or maximum street yard).
Section 07.600 allows a number of density bonuses for infill sites within 1,000 feet of an existing
or planned (by DTC) transit stop. For bus-oriented infill, bonuses include a 12-percent increase,
and reduced open space requirements. Rail-oriented infill can get up to a 30-percent bonus with
reduced open space, and additional building height allowed.
According to the General Use Tables, single-family attached dwellings are only allowed in the
TN, ST, and Neighborhood Conservation (NC) districts. Apartment conversions (of singlefamily dwellings) are allowed as a limited use in the S, TN, ST, and NC districts. Commercial
apartments, such as an apartment above a store, are allowed in Villages and Hamlets (S), and as a
limited use in the CN, CR, and TN districts. Apartments are only allowed as a limited use in the
TN, ST, and NC districts.
Section 05.520 D. allows a developer to acquire the development rights of a second parcel
located in the same planning district, and apply the development rights to the first parcel. The
second parcel would then be subject to a conservation easement. Any traffic impact study would
be based upon the proposed density of the receiving property including the transfer of all
development rights (Section 07.210 E).
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
64
D. Traffic Calming
No separate traffic calming research studies were conducted to develop recommendations
specific to Delaware. In developing the Traffic Calming Design Manual, however, DelDOT
conducted a review of the current literature, which can be found in the previous section.
Traffic Calming Implementation Activities
Adopted by DelDOT in 2000, the Mobility Friendly Design Standards include traffic calming
measures. The standards were developed for local subdivision streets and minor collector
subdivision streets. Local subdivision streets require a 20 mph design speed (versus 25 mph) and
full array of horizontal and vertical traffic calming measures that are consistent with 25 mph
design speeds, except on emergency response routes. Minor collector subdivision streets require
a 25 mph design speed (versus 30 mph) and a full array of horizontal and vertical traffic calming
measures consistent with 20 mph design speeds.
Traffic calming is defined by the Institute of Transportation Engineers (ITE) as “changes in
street alignment, installation of barriers, and other physical measures to reduce traffic speeds
and/or cut-through volumes in the interest of street safety, livability, and other public purposes.”
Adopted in 2000, DelDOT’s Traffic Calming Design Manual was developed in response to
requests from citizens for slower traffic in their neighborhoods and improved safety for
pedestrians and bicyclists.
The manual establishes procedures for selecting and implementing traffic calming measures,
appropriate applications, geometric design of traffic calming measures, and conventions for
signing and marking traffic calming measures. The manual does not address non-engineering
solutions such as landscaping, enforcement, or education campaigns, which are out of the
purview of the Department of Transportation. The guidelines contained in this manual,
considered more conservative than policies adopted in other states and countries, may require
revision as projects are implemented.
The manual may be used to resolve existing problems. However, developers are encouraged to
incorporate traffic calming measures in new developments. Although some projects may be
localized, DelDOT prefers to adopt area-wide approaches to prevent traffic problems from
relocating from one street to another.
DelDOT’s traffic calming toolbox includes volume control measures such as full- and half-street
closures, diverters, medians, and forced-turn islands. Vertical speed control measures include
speed humps, speed tables, and raised crosswalks. Horizontal speed control measures include
mini-traffic circles, roundabouts, chicanes, and realigned intersections. Narrowing can be
accomplished using bulbouts, neckdowns, chokers, and center islands. Not all traffic calming
techniques are appropriate to all roadways. They are considered most applicable to local
residential or subdivision streets. Some highly-urban pedestrian streets, however, may be
appropriate candidates for traffic calming.
The UDC refers to traffic calming in section 20.110 E, which states “Road connections shall
seek to avoid external automobile trips through the employment of super blocks, stub streets,
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
65
connecting open space, bicycle-pedestrian ways, and other design techniques and devices”
(emphasis added).
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
66
E. Interconnectivity
Although the concept of interconnectivity has been recommended by many sources, very little
research has been conducted in Delaware on this issue.
Implementation
DelDOT’s Mobility Friendly Design Standards require subdivisions using these standards to be
designed with a connectivity index of 1.4. However, the use of the standards is optional and not
required of all new development. As of the date of this publication, no developer in Delaware
has elected to use these standards.
The UDC strongly encourages interconnectivity in the following sections:
• Section 01.015 D. Public infrastructure “ensures safe and convenient traffic control and
movement including a reduction or prevention of congestion on public streets,
convenience of access, multiple modes of transportation, and an interconnected and wellplanned street system.”
• Section 20.110 E. Street and circulation patterns shall provide for the safe, efficient, and
convenient movement of vehicular and pedestrian traffic. Vehicular travel lanes,
pedestrian movement systems, and parking should be separated. Within the context of
the overall community development, the internal circulation system should promote and
encourage the increased use of pedestrian and bicycle movement among residential, local
shopping, schools and other areas. Road connections shall seek to avoid external
automobile trips through the employment of super blocks, stub streets, connecting open
space, bicycle-pedestrian ways, and other design techniques and devices.”
• Section 20.230 B. Local streets “shall be designed to discourage through traffic.
However, developments within super blocks shall be interconnected to reduce loadings
on arterials and collectors.”
• Section 20.230 F. Subdivisions “shall be connected to each other to provide reasonable
access within a super block.”
Other Delaware Activities Related to Interconnectivity
DelDOT, through the Delaware Center for Transportation at the University of Delaware, initiated
the Sub-Division Interconnectivity Study in 2003 to study the effectiveness of vehicular
interconnectivity between adjacent subdivisions. The study, which is being conducted by the
University of Delaware’s Institute for Public Administration (IPA), will compare communities
that have incorporated interconnectivity with similar communities that have not. The purpose of
the study is to determine the effects of interconnectivity on individual communities and identify
community, design, and traffic calming issues. As of the date of this publication, the study is in
the early stages of the literature review, comparing characteristics of possible communities for
study, and performing initial interviews. No conclusions, therefore, can be drawn at this time.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
67
F. School Transportation/Location
Research and Recommendations
The report Planning Delaware’s School Needs: Issues of Location, Design and Infrastructure
was developed for the state in 2001 by Stephanie Moody and David Edgell (then) of the
University of Delaware’s Institute for Public Administration. The authors report that a number
of issues affect the siting of schools in Delaware, including proximity to towns and
municipalities, feeder and growth patterns, access to water and sewer, property size, state
spending map, overall growth in the area, and GIS data. The Delaware Department of Education
recommends that four potential sites should be selected and submitted to the state for LUPA
review for each planned new school.
The process of determining the number of new schools needed in Delaware has been
complicated by charter schools, school choice, and neighborhood schools legislation. It is
difficult for school districts to estimate how many students will enroll in particular schools in a
given year. Additionally, some students who choose alternate schools may return to public
schools during the course of the year. In addition, Delaware has one of the highest ratios of
private schools per pupil in the nation.
There was an excess design capacity of 14,308 students in public schools statewide in 2000.
Certain school districts were (and still are) operating above capacity and need new school
buildings. The excess capacity tends to be located in older existing communities, while the lack
of capacity occurs mostly in newly developing areas.
There was consensus among panel members at the forum on “Planning Delaware’s School
Needs: Issues of Location Design and Infrastructure” that the school construction process has
some problems and needs improvement. Some of the problems identified included the length of
time required to get approvals and build a school, community involvement, cooperation with
state agencies, the design approval process, and the incorporation of other community uses into
school buildings. Below are some issues facing public schools:
• Delaware’s school construction process can take as long as five years.
• Referendums need to be reviewed and the Certificate of Need process needs to be
shortened.
• Charter schools do not need to follow the same approval/construction process as do
public schools.
• School sites could be pre-selected using public involvement and selected sites could be
documented within county and municipal comprehensive plans.
• Communications could be improved between agencies, governments, school districts, and
schools, including charter schools.
• Building materials across the state could be standardized and a standard of minimum
requirements could be developed for building schools.
• Additional topics for research and discussion include funding issues, school-building
design issues, process/pre-planning of sites, and issues related to population projections.
• New Castle County has exempted schools from some environmental rules and conducts
accelerated site reviews, which speeds the process considerably.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
68
The School Construction Planning Committee’s 2002 report Building Quality Schools:
Revisions to the School Construction Formula and Recommendations on Standards makes the
following recommendations for the design, funding, and construction of schools in Delaware:
• Size of classrooms should be increased and additional space allocated to address federal
and state guidelines.
• Minimum set of material-based construction standards should be established for new
construction and renovations.
• Recently approved plans and examples should be provided to school districts in the early
stages of the planning process. The use of standardized plans, however, was not
recommended.
• Complete review of the current custodial program should be conducted with an eye on
facilitating community use of school facilities.
The Future of School Siting, Design and Construction in Delaware (Hunter and Sawak) reports
that Delaware had 16 public school districts, 3 vocational technical schools, and 10 charter
schools in 2002. The total number of students in these schools was 115,484. An additional
27,299 children attended the 631 non-public schools in Delaware and 2,288 children were homeschooled. It is anticipated that the state’s population will increase 30 percent by the year 2030,
requiring many new schools to be built. Some districts are experiencing shrinking enrollments
while others are over capacity. Livable Delaware encourages schools to be located within areas
designated for growth, where infrastructure exists or will be provided. Below are the
recommendations of this report:
• Research and review practices to better synchronize DelDOT’s and DOE’s processes
relating to school-siting issues.
• Research and develop a design standard for the interior of school buildings, analyze
design methods to discourage “cookie-cutter” schools. Research the possibility of leasepurchase as a method of financing schools and how to create schools without legislation.
• Design a new and more efficient Certificate of Necessity (CN) process that would
address land acquisition and construction and determine the compatibility of a site with
state and local comprehensive plans and the availability of infrastructure. Research CN
existing practices in other states.
• Analyze the relationship between school infrastructure and perceived enrollment growth.
Review infrastructure issues related to school siting. Research the possibility of
establishing a land bank whereby the state could purchase land in growing areas that
could later be used for schools. Research, also, the K-12 Campus Approach.
• Research the possibility of compatible community uses to make the most efficient use of
school infrastructure. Identify possible sites. Continue research into cost-sharing between
the schools and community uses.
• Review how charter schools are sited and determine how to bring them into the state
siting process.
• Research and review school-financing options.
In addition, school bus routes need to be planned and designated as part of the street network of
proposed subdivisions and communities as a result of recommended reduced minimum curb
return radii, according to WILMAPCO’s Mobility Friendly Design Standards.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
69
Implementation Activities Related to Schools and School Transportation
The Delaware Transit Corporation’s DTC Bus Stop and Passenger Facilities Policy, which was
adopted by the Delaware Department of Transportation in March 2000, includes the following
with respect to local and Intercounty bus service with low-transit density: “Stop locations will
generally be based on activity centers rather than distance. In rural areas, a preference may be
given to locate bus stops at highly visible locations such as commercial areas, convenience
stores, or schools.”
The UDC provided little regulation regarding the design and location of schools. Schools,
including colleges and universities, are allowed by right in the following zoning districts: OR,
CR, and BP (Business Park). They are allowed as a limited use in the following zoning districts:
TN, ST, Industrial (I), CN, S, Suburban Estate (SE), NC, and SR.
With respect to transportation, sidewalks may be required in areas where they may not otherwise
be required, such as when schools are present. In addition, Section 20.110 E states, “All street
and circulation patterns shall provide for the safe, efficient, and convenient movement of
vehicular and pedestrian traffic. Vehicular travel lanes, pedestrian movement systems, and
parking should be separated. Within the context of the overall community development, the
internal circulation system should promote and encourage the increased use of pedestrian and
bicycle movement among residential, local shopping, schools, and other areas.”
Section 21.131 states, “All residential subdivisions and land developments shall have an internal
street or accessway system capable of accommodating school bus traffic.” To facilitate this
access, the vehicular circulation pattern must incorporate a system of circular or loop streets.
Other Delaware Activities Related to School Siting and Design
The University of Delaware’s Institute for Public Administration (IPA) is currently conducting a
study reviewing the Certificate of Necessity requirements and process. Additionally, IPA plans
to conduct a survey of school siting and design practices throughout the country. When
completed, the information will be helpful for updating Delaware’s practices.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
70
G. Trails
As of the date of this publication, no Delaware-specific design standards or research for trails
were found to exist. DNREC has developed a Greenways Master Plan, but copies were not
available in time for review.
Implementation
The UDC mentions trails in the following sections:
• Section 04.330 states that pedestrian, bike, or equestrian trails may be located within a
bufferyard.
• Table 10.210 allows trails to be located within all types of required open space.
• Section 20.225 B. 6 states, “Open space shall be interconnected with open areas or
greenways on abutting parcels wherever possible and may provide provisions for
pedestrian pathways for general public use, to create linked pathway systems within the
County where appropriate.”
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
71
H. Conclusion
In terms of policy, Delaware, WILMAPCO, and New Castle County have fully committed
themselves to improving transportation and land use planning in the region and pursuing the
concept of mobility friendly design. Many studies have been completed that review and make
recommendations for all aspects of mobility friendly design, with the possible exception of trails.
Some issues such as interconnectivity and schools are currently being studied with
recommendations to come. At the same time, progress toward implementation of the
recommendations has been made. More work, however, needs to be done.
Attempts have been made to implement the concepts throughout the county. Some of the studies
have led to actual projects on the ground; others have not. Area studies have been completed by
DelDOT, WILMAPCO, and New Castle County, with varying degrees of success, such as:
• Route 40 Corridor Improvements Study
• Centreville Village Plan
• Old Newark Traffic Calming Study
• Wilmington Initiatives
• Claymont Community Manual of Design Guidelines
• Edgemoor Transit Oriented Development Analysis
The next step in this process is to review the implementation efforts against the
recommendations to measure success and identify areas where more work is needed. Many of
the measures will not be easy to implement and the limited available research suggests that some
measures may be more effective than others.
Finally, although implementation activities affecting new development are important for the
future, considerable effort should be focused on implementation activities that will benefit the
majority of New Castle County residents who live in already-developed areas of the county.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
72
PART IV. APPENDICES
A.
B.
C.
D.
E.
Works Cited: Delaware Sources.....................................................................74
Works Cited: National Sources ......................................................................76
Recommended Websites ................................................................................79
Recommended Books.....................................................................................80
State Strategies Map for New Castle County.................................................83
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
73
Works Cited
Delaware Sources
Athey, Lorene J., Eugene E. Abbott, and William Hellmann. “Churchmans Crossing
Infrastructure Investment Project.” Transportation Research Record 1685 Washington:
National Academy Press (1999): 39-50.
Delaware. Dept. of Transportation. Churchmans Crossing Study: Final Draft October 30, 1996.
Newark: WILMAPCO, 1996.
Delaware. Dept. of Transportation. Mobility Friendly Design Standards. Dover: 2000.
Delaware. Dept. of Transportation. Policy Implement DTC-05 Bus Stop and Passenger Facilities
Policy. Dover: 2000.
Delaware. Dept. of Transportation. Standards and Regulations for Subdivision Streets and
Highway Access. Dover: 1984.
Delaware. Dept. of Transportation. Traffic Calming Design Manual. Dover: 2000.
Delaware. Office of State Planning Coordination. Shaping Delaware’s Future: Managing
Growth in 21st Century Delaware Strategies for State Policies and Spending. Dover: 1999.
Hunter, Anna Wojewodzki, and Camille Sawak. The Future of School Siting, Design and
Construction in Delaware Report and Recommendations. Proc. of a Summit. Newark:
Institute for Public Administration, U of Delaware, 2003.
Kikuchi, Shinya, Christine Haas, and Mitsuru Tanaka. Micro-Level Transit Accessibility Study.
Delaware Transportation Institute and U of Delaware, 2001.
LDR International. Traditional Neighborhood Development (TND) Guidelines. Delaware: New
Castle County Department of Land Use, 1997.
Moody, Stephanie, and David Edgell. Planning Delaware’s School Needs: Issues of Location,
Design, and Infrastructure. Proc. of a Delaware Public Policy Forum. Newark: Institute for
Public Administration, U of Delaware, 2001.
New Castle County. Dept. of Land Use. Unified Development Code. 1998 and subsequent
revisions. <http://www.co.new-castle.de.us/Landuse/Landuse1.htm>.
School Construction Planning Committee. Building Quality Schools: Revisions to the School
Construction Formula and Recommendations on Standards. Report. Delaware Department of
Education and Institute for Public Administration, U of Delaware. Newark: Institute for
Public Administration, U of Delaware, 2002.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
74
Vanasse Hangen Brustlin, Inc. Review of Transit Oriented Development and Transit Overlay
Districts. Watertown: 1997.
Vanasse Hangen Brustlin, Inc. Transit Overlay Districts and Transit Friendly Design Standards
for New Castle County. Watertown: 1997.
WILMAPCO. Mobility Friendly Design Standards. Newark: WILMAPCO, 1997.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
75
Works Cited
National Sources
“Blueprint for a Walkable Community: Florida’s 12-Step Program.” Prevention May 1994: 100103.
Butler, Kent, Susan Handy, and Robert G. Patterson. Planning for Street Connectivity: Getting
from Here to There. APA Planning Advisory Service, 2003.
Calthorpe, Peter. The Next American Metropolis: Ecology, Community and the American
Dream. New York: Princeton Architectural Press, 1993.
Cervero, Robert. Transit-Supportive Development in the United States: Experiences and
Prospects. Federal Transit Administration. Washington: Federal Transit Administration,
National Technical Information Service, 1993.
Cervero, Robert. “Rail-Oriented Office Development in California: How Successful?”
Transportation Quarterly 48.1 (1994): 33-44.
Community Planning Workshop. Connecting Transportation & Land Use Planning Street
Connectivity. Eugene: U of Oregon, 2003.
Daisa, James M. P.E., Tom Kloster, and Richard Ledbetter. Does Increased Street Connectivity
Improve the Operation of Regional Streets? Case Studies from the Portland Metro
Regional Street Design Study. Conference on Transportation, Land Use and Air Quality:
Making the Connection. Reston: American Society of Civil Engineers, 1998.
Ewing, Reid. Pedestrian- and Transit-Friendly Design: A Primer for Smart Growth.
Washington: International City/County Management Association and Smart Growth
Network, 1999.
Ewing, Reid H. Traffic Calming: State of the Practice. Washington: Institute of Transportation
Engineers, 1999.
Frank, L.D. and Gary Pivo. “The Impacts of Mixed Use and Density on the Utilization of Three
Modes of Travel: Single-Occupant Vehicle, Transit, and Walking.” Transportation
Research Record 1466 Washington: National Academy Press (1994): 44-52.
Giuliano, Genevieve. Land Use Policy and Transportation: Why We Won’t Get There From
Here. Los Angeles: U of California, 1997.
Hillman, Mayer. “The Impact of Transport Policy on Children’s Development.” Canterbury Safe
Routes to Schools Project Seminar. Canterbury Christ Church University College, 29
May 1999.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
76
Howlett, Debbie. “Study finds traffic congestion bad and getting worse.” USA Today on the
Web 30 Sep. 2003. 6 Oct. 2003 <http://www.usatoday.com/news/nation/2003-09-30congested-highways_x.htm>.
Kirschbaum, Julie B., et al. Designing Sidewalks and Trails for Access: Part 2 of 2 Best Practices
Design Guide. Nevada: Beneficial Design Inc., 2001.
Kitamura, R. Mokhtarian, and P. L. Laidet. “A micro-analysis of land use and travel in five
neighborhoods in the San Francisco Bay Area.” Transportation 24 (1997): 125-158.
Lawrence, Barbara Kent, and Jannell Weihs. Table: State Guideline Information. 2003. Council
for Educational Facility Planners. <www.cefpi.org/pdf/state_guidelines.pdf>.
Metropolitan Council. Creating Livable Streets: Street Design Guidelines for 2040. 2nd ed.
Portland: Metropolitan Council, 2002.
Miller, Eric J. and Amer Shalaby. “Evolution of Personal Travel in Toronto Area and Policy
Implications.” Urban Planning & Development (2003): 1-26.
Miller, John S., and Lester A. Hoel. “The ‘smart growth’ debate: best practices for urban
transportation planning,” Socio-Economic Planning Sciences 36 (2002): 1-24.
Pedestrian and Bicycle Information Center. “Rails and Trails: Design of Trails.” 2000.
Walkinginfo.org. <www.walkinginfo.org/rt/design.htm>.
Pedestrian and Bicycle Information Center. “Shared Use Paths (Trails).” 2000.
Bicyclinginfo.org. <www.bicyclinginfo.org/de/shared.htm>.
Petersmark, Karen and Risa Wilkerson. Land Use Affects Public Health. 2003. Michigan Dept.
of Community Health and Governor’s Council on Physical Fitness Health and Sports.
<http://www.michiganlanduse.org/resources/councilresources/LU_Affects_Public_Healt
h.pdf>.
Public Rights-of-Way Access Advisory Committee. Building a True Community: Final Report.
Washington: The Access Board, 2001.
Robinette, Gary O., ed. Barrier-free Exterior Design: anyone can go anywhere. New York: Van
Nostrand Reinhold Company, 1985.
Roper, W.L., et al. Health and Smart Growth: Building Health, Promoting Active Communities,
Translation Paper 11. Miami: Funders’ Network for Smart Growth and Livable
Communities, 2003.
Sarker, Mohsin J., et al. “Impact of Transportation Infrastructure Development on Modal
Choice.” Journal of Urban Planning and Development June (2002): 59-76.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
77
Southworth, Michael. “Walkable Suburbs? An Evaluation of Neotraditional Communities at the
Urban Edge.” Journal of the American Planning Association 63.1 (1997): 28-44.
Stone, J.R., M.D. Foster, and C.E. Johnson. “Neo-traditional neighborhoods: A solution to traffic
congestion.” Site Impact Traffic Assessment: Problems and Solutions. Ed. Robert E.
Paaswell, et al. Proc. of a Conference in Chicago. 8-10 June 1992. New York: American
Society of Civil Engineers, 1992.
Texas Transportation Institute. 2003 Urban Mobility Study. College Station: Texas A&M U,
2003.
United States. Environmental Protection Agency. Travel and Environmental Implications of
School Siting. EPA 231-R-03-004. Washington: 2003.
Victoria Transport Policy Institute. “Transit Oriented Development: Using Public Transit
to Create More Accessible and Livable Neighborhoods” Transportation Demand
Management (TDM) Online Encyclopedia. 2003. <www.vtpi.org/tdm>.
Wallwork, Michael J. “Traffic Calming.” The Traffic Safety Toolbox. Washington: Institute of
Transportation Engineers, 1993.
“What is Universal Design?” The Center for Universal Design Home Page. 1 Apr. 1997. NC
State U. 2003 <http://www.design.ncsu.edu:8120/cud/univ_design/princ_overview.htm>.
Zelinka, Al, and Dean Brennan. SafeScape: Creating Safer, More Livable Communities through
Planning and Design. Illinois: American Planning Association Planners Press, 2001.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
78
C. Recommended Websites
www.activelivingbydesign.org
Active Living by Design is a national program of the Robert Wood Johnson Foundation
established to evaluate innovative approaches to increase physical activity through community
design, public policies, and communications strategies.
www.apta.com
The American Public Transportation Association is a Washington-based advocacy organization
that leads the way in increasing, expanding, and strengthening the role of public transportation.
www.transportationequity.org
The Center for Community Change is committed to strengthening low-income communities
through a diverse range of programs. The center’s Transportation Equity program addresses the
issues related to movement and people.
www.ctaa.org
The Community Transportation Association of America has been bringing together community
members to identify mobility challenges and design transit solutions since 1989. The
organization is founded upon a vision of the future of transportation based on the fundamental
American values of freedom, independence, dignity, and choice.
www.bikewalk.org
The National Center for Bicycling and Walking is the major program of the Bicycle Federation
of America, a national nonprofit corporation established in 1977. The center’s mission is to
create bicycle-friendly and walkable communities.
www.pps.org
The Project for Public Spaces is a nonprofit organization dedicated to creating and sustaining
public places that build communities, providing technical assistance, education, and research.
www.transact.org
The Surface Transportation Policy Project.
www.vtpi.org
The Victoria Transport Policy Institute.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
79
D. Recommended Books
Carfree Cities, by J.H. Crawford
The author, a former consultant to the New Jersey Department of Public Transportation,
examines our modern quality of life and concludes that acceptance of the automobile is at the
root of deteriorating social, physical and global environments. He includes a reference design for
a new carfree city and gives suggestions for adapting existing cities, such as New York City, and
building new ones.
The Mayor’s Institute: Excellence in City Design, edited by James S. Russell and Mark Robbins
This book offers guidance on using architecture, landscape architecture, art, urban design, and
planning to improve space in the public realm. Since the late 1990s, the National Endowment for
the Arts, under the direction of Mark Robbins, has been promoting design excellence through an
ambitious series of symposia, best-case design studies, and prototype projects. The results of the
programs are now documented in a new series of publications, each focusing on design in the
public realm and the potential for innovative architecture, landscape architecture, and planning.
Mobility: A Room With a View, by Francine Houben and Luisa Maria Calabrese (Editor)
The theme of the first Rotterdam International Architecture Biennial was mobility, as it relates to
the city and the landscape, and the design culture associated with it. Held between May and July
2003, the biennial brought together numerous universities, architects, urbanists, spatial planners
and designers to swap experiences and discuss new strategies for giving shape to (car) mobility.
This unique book shows the results of this international research in its various forms: statistics,
photography, text, visual collage and design proposals. These together give a tangible and
insightful look at the mobile cultures found in a wide range of cities and countries, from Mexico
City, Hong Kong and Guangzhou, to Djakarta, Budapest, the Ruhr Valley, Beirut, Los Angeles,
Tokyo, Peking and Holland. The aim of the publication is twofold: on the one hand, to
understand infrastructures and motorway culture by studying their different cultural and
geographical contexts; on the other, to draw up an agenda for the future, one that establishes the
role to be played by various design disciplines.
Urban Design: Streets and Square, by Cliff Moughtin
This book, part of a series of four, offers a detailed analysis of urban design, covering the streets,
squares and buildings making up the public face of towns and cities. It outlines the theory of the
principal features of urban design from which method is developed and provides a better
understanding of the main elements of urban design. This includes the arrangement, design and
details of the streets and squares, and the roles they play in city planning.
This book includes chapters on “Sustainable Urban Design” and “Visual Analysis,” introducing
the latest theories and influences in the field and bringing greater practical significance to the
book. Cliff Moughtin explores the street and square in terms of function, structure and
symbolism and examines fine examples in their historical context. These are set against the
background of the laws of urban design composition, culled from Renaissance and modern
writers.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
80
Urban Design: Methods and Techniques, by Cliff Moughtin
This book deals with a wide range of techniques used in the urban design process. It then goes on
to relate these techniques to a unique, comprehensive account of method. A method of urban
design is developed that has sustainability and environmental protection at the center of its
philosophy. Previously, literature regarding the urban design method has been almost totally
neglected; this book introduces the topic to the reader.
A number of techniques are illustrated by example or case study. Where techniques are discussed
they are located within the structure of the design process. The book develops a logical
framework for a process, which includes problem definition, survey, analysis, concept
generation, evaluation and implementation. It is this framework, which leads to the development
of an urban design method.
Asphalt Nation: How the Automobile Took Over America, and How We Can Take It Back, by
Jane Holtz Kay
Asphalt Nation is a powerful examination of how the automobile has ravaged America’s cities
and landscape over the past 100 years, together with a compelling strategy for reversing our
automobile dependency. Jane Holtz Kay provides a history of the rapid spread of the automobile
and documents the huge subsidies commanded by the highway lobby, to the detriment of onceefficient forms of mass transportation. Demonstrating that there are economic, political,
architectural, and personal solutions to the problem, she shows that radical change is entirely
possible.
Comeback Cities: A Blueprint for Urban Neighborhood Revival, by Paul S. Grogan and Tony
Proscio
Comeback Cities shows how innovative, pragmatic tactics for ameliorating the nation’s urban
ills have produced results beyond anyone’s expectations, reawakening America’s toughest
neighborhoods. In the past, big government and business working separately were unable to
solve the inner-city crisis. Rather, a blend of public-private partnerships, grassroots nonprofit
organizations, and a willingness to experiment characterize what is best among the new
approaches to urban problem-solving. Pragmatism, not dogma, has produced the charter-school
movement and the police’s new focus on “quality-of-life” issues. The new breed of big city
mayors has welcomed business back into the city, stressed performance and results at city
agencies, downplayed divisive racial politics, and cracked down on symptoms of social disorder.
As a consequence, America’s inner cities are becoming vital communities once again.
There is much yet to be done, but Grogan and Proscio base their optimism on a number of trends
that could dramatically multiply the impact of the grassroots community development industry.
The authors point to unprecedented access to capital and credit, astonishing reductions in violent
crime, and substantial overhauls of public housing, welfare, and public schools already underway
as harbingers of an inner-city revival. Through a mixture of analysis and storytelling, Grogan and
Proscio argue convincingly that the conditions are ripe – the infrastructure is in place – to turn a
source of national shame into a source of national pride.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
81
Changing Places: Rebuilding Community in the Age of Sprawl, by Richard Moe and Carter
Wilkie
America’s preservation movement has long fought the destructive force of so-called urban
renewal, where highways and shopping malls rise up on the rubble of former thriving
downtowns. Now communities are in the fight of their lives against urban sprawl – boundless
development that devours the countryside and leaves cities and small towns in ruins – a fight that
is as much about preserving our civic space as our landscape. In Changing Places, authors
Richard Moe and Carter Wilkie give examples of how America’s embattled towns are defending
themselves against corporate giants and depressed economies, from community activists
restoring pride in their inner cities to municipalities breathing life back into historic downtowns.
At once cautionary and redemptive, Changing Places has been hailed by David McCullough as
“a call to arms” that should be read by everyone alarmed.
Mobility Friendly Design Standards: A Framework for Delaware
DRAFT: February 2004
82
Institute for Public Administration
College of Human Services, Education & Public Policy
University of Delaware
180 Graham Hall
Newark, DE 19716-7380
phone: 302-831-8971 e-mail: ipa@udel.edu
fax: 302-831-3488
www.ipa.udel.edu
The Institute for Public Administration (IPA) is a public service, education and research center that links the resource
capacities of the University of Delaware with the complex public policy and management needs of governments and
related nonprofit and private organizations. IPA provides direct staff assistance, research, policy analysis, training,
and forums while contributing to the scholarly body of knowledge. Program areas include civic education, conflict
resolution, health care policy, land use planning, organizational development, school leadership, state and local
management, water resources planning, and women's leadership. IPA supports and enhances the educational
experiences of students through the effective integration of applied research, professional development opportunities,
and internships. Jerome Lewis is the director of the Institute and can be reached at 302-831-8971.
An Equal Opportunity/Affirmative Action Employer
The University of Delaware is committed to assuring equal opportunity to all persons and does not discriminate on the basis
of race, color, gender, religion, ancestry, national origin, sexual orientation, veteran status, age, or disability in its educational
programs, activities, admissions, or employment practices as required by Title IX of the Education Amendments of 1972, Title
VI of the Civil Rights Act of 1964, the Rehabilitation Act of 1973, the Americans with Disabilities Act, other applicable statutes
and University policy. Inquiries concerning these statutes and information regarding campus accessibility should be referred to
the Affirmative Action Officer, 305 Hullihen Hall, (302) 831-2835 (voice), (302) 831-4563 (TDD).