The Benefits and Impacts of Roadway
Access Management
2000 APA Upper Midwest
Regional Planning Conference
Duluth, Minnesota
August 2000
Presentation Outline
• What is access management?
– An example corridor
• What are the benefits of managing access?
• What are the main techniques and treatments for
managing access?
• How does access management effect business vitality
and commercial development?
• How can access management be implemented?
• Conclusions
What Is Access Management?
• “Access Management is the process that provides
access to land development while simultaneously
preserving the flow of traffic on the surrounding
road system in terms of safety, capacity, and
speed”.
(Source: Federal Highway Administration)
A Key Goal of Access Management
• Maintain the functional integrity of the
roadway system
Functional Integrity
• Reserve high speed, high capacity roads for high
speed, long-distance travel
• Maintain a “hierarchy” of roads
• Balance traffic movement and access to adjacent
land by providing land access compatible with the
roadway classification
Functional Integrity
Freeway
Arterial
Through
Traffic
Movement
Collector
Local
Access to Property
Presentation Outline
• What is access management?
– An example corridor
• What are the benefits of managing access?
• What are the main techniques and treatments for
managing access?
• How does access management effect business vitality
and commercial development?
• How can access management be implemented?
• Conclusions
Crashes Are Concentrated
Along Arterial Corridors
Crash Density Varies Greatly
Why? Variations In Access
Douglas Avenue:
Well-Managed Portion
Urbandale, Iowa
Douglas Avenue:
Moderately Well-Managed Portion
Urbandale, Iowa
Douglas Avenue:
Poorly Managed Portion
Des Moines, Iowa
Douglas Avenue:
Poorly Managed Portion
Des Moines, Iowa
Douglas Avenue:
Poorly Managed Portion
Des Moines, Iowa
Presentation Outline
• What is access management?
– An example corridor
• What are the benefits of managing access?
• What are the main techniques and treatments for
managing access?
• How does access management effect business vitality
and commercial development?
• How can access management be implemented?
• Conclusions
What Are the Main
Benefits of Managing Access?
• Improved safety
– Reduction in crashes and crash rates
• Better traffic operations
– Improved traffic LOS, capacity, and speed
• Other public benefits
– For pedestrians, bicyclists, public transit riders, taxpayers,
and the environment
• Potentially, a better environment in which to do
business and pursue economic development
Safety: Driveway Density
And Crash Rates Are Strongly Related
Safety: Crash Rates Are Significantly Lower
On Better Managed Roads
Safety: Crash Rates Are Significantly Lower
On Better Managed Roads
• Based on seven
detailed “before and
after” Iowa case
studies
• Case studies show
nearly a 40 percent
average reduction in
accident rates after
access management
projects were
completed.
7
Before
6
After
5
4
3
2
1
0
Accident Rate
(per MVMT)
Safety: Certain Types of Crashes
Are Reduced Significantly When Access Is
Managed Better
Total
Other
Right Angle
Left/Broadside
Rear End
0
50
100
150
200
250
Before
After
Operations: Capacity Is Higher
On Better Managed Roads
Operations: Travel Speeds Are Higher
On Well-Managed Roads
Presentation Outline
• What is access management?
– An example corridor
• What are the benefits of managing access?
• What are the main techniques and treatments for
managing access?
• How does access management effect business vitality
and commercial development?
• How can access management be implemented?
• Conclusions
How Access Is Managed
• The functional integrity of the roadway
system can be maintained by:
– Limiting conflict points
– Separating conflict points
– Removing turning traffic from through traffic
lanes
Conflict Points at an Intersection
Limiting Conflict Points: Medians
Separating Conflict Points: Why?
• Drivers can only mentally process one
conflict point at a time
• Separation provides enough time and space
for drivers to react to the unexpected
• Conflict points represent opportunities for
accidents, congestion, and delay
Separating Conflict Points:
Corner Clearance and
Driveway Spacing Standards
Facilitating Turning Movements:
Important Strategies and Design Features
• Increased turning radii
• Increased driveway width
– (while still maintaining well-defined driveways)
•
•
•
•
Decreased driveway slope
Including dedicated turn lanes or tapers
Improved sight distance for turning traffic
Improved internal site design
Facilitating Turning Movements
Steeper Driveways =
Slower Turns = More Conflict
Common Access
Management Treatments
•
•
•
•
•
•
Driveway consolidation
Corner clearance
Raised medians
Raised medians at intersections
Two-way left-turn lanes (TWLTL)
Alternative access-ways
– Frontage roads
– Backage roads
– Internal circulation systems
New Development With Excellent
Internal Circulation Design
New Home Depot and Super Target Stores,
Delaware Avenue, Ankeny Iowa
Presentation Outline
• What is access management?
– An example corridor
• What are the benefits of managing access?
• What are the main techniques and treatments for
managing access?
• How does access management effect business
vitality and commercial development?
• How can access management be implemented?
• Conclusions
Access Management
and Business Vitality
• Business owners often oppose access changes or
restrictions (sometimes very aggressively)
• Overall impacts on businesses are neutral to
positive when access is managed retroactively
• Iowa case study results show:
– Similar business failure rates
– Improved retail sales levels versus other locations in the
community
– Improved potential for redevelopment/new development
– Some individual businesses will be negatively impacted
Five Year Comparative
Business Survival Rates
70
60
50
40
Community
Corridor
30
20
10
0
Ames
Ankeny
Clive
Fairfield
Spencer
Statewide
Note: Based on a five year period bracketing project completion. For corridors,
business name changes or moves are counted as failures. First round projects only.
Case Study Corridor
Sales Tax Revenue Growth
Retail Trade Growth Trends, 1990s
Average, Without Clive
Average
Case Studies
West Des Moines
Des Moines
Coralville
Bettendorf
Spencer
Fairfield
Clive
Ankeny
Ames
0
50
100
150
200
250
300
350
Index, 1990=100
Corridor Index
Community Index
400
450
500
Same Businesses Sales
After Project Completion
Reported Sales Trend Post-Project
29%
6%
45%
20%
Decrease
Same
Increase
Uncertain/No response
Source: Opinion survey of business owners and managers.
Businesses Reporting A Loss Of Sales
After Project Completion
• Nine of 162 businesses surveyed (6%) reported sales
losses; these were:
–
–
–
–
–
–
–
Two gasoline stations (both Des Moines--Median)
Two real estate offices (Ankeny--Median and Coralville--TWLTL)
A convenience store (Bettendorf--TWLTL)
A supermarket (Ankeny--Median)
A tanning salon (Clive--Median)
A music store (Coralville--TWLTL)
A fast food restaurant (Coralville--TWLTL)
• Five of these were “auto-oriented” businesses
• Five of these involved medians while four involved twoway left-turn lanes
Businesses Reporting Any Customer
Complaints About Highway Access
After Project Completion
Businesses Reporting Customer
Complaints
28%
72%
Complaints reported
No complaints
Businesses Reporting Customer Access
Complaints, By Type
Customer Access Complaints
By Business Type
28%
43%
Restaurant/fast food
Auto service/sales/gas station
Hotel/motel
Insurance/real estate
Other business type
19%
6%
4%
Well-Managed Corridors May Prove
More Attractive To Developers
(Two Adjacent Corridors in Des Moines, Iowa)
SE 14th Street
Army Post Road
Presentation Outline
• What is access management?
– An example corridor
• What are the benefits of managing access?
• What are the main techniques and treatments for
managing access?
• How does access management effect business vitality
and commercial development?
• How can access management be implemented?
• Conclusions
Implementing Access Management
• In most states, roadway jurisdictions are legally
responsible for managing access and providing access to
properties
• State legislation usually spells out the regulatory powers of
roadway jurisdictions
• Road agencies manage access through access rights
purchases, project design, and driveway permitting
• Local governments also manage access via land use
regulations, particularly when zoning is changed or land is
subdivided
Implementing Access Management
• Involvement of and cooperation among
many parties is essential if access is to be
managed successfully:
–
–
–
–
–
Road jurisdictions
Transportation planning agencies
Land use planning and regulatory organizations
Business owners
Land developers
Presentation Outline
• What is access management?
– An example corridor
• What are the benefits of managing access?
• What are the main techniques and treatments for
managing access?
• How does access management effect business vitality
and commercial development?
• How can access management be implemented?
• Conclusions
Who Wins When Access
Management Is Done Right?
• Motorists: safer, less congested roads
• Taxpayers: less expensive roads
• Most business persons and their customers:
improved business and commercial
environment
• Communities as a whole: environmental
and other benefits
Contact:
David J. Plazak
Center for Transportation Research and Education,
ISU Research Park, Ames, IA 50010-8615
Telephone:
Fax:
E-mail:
URL:
(515) 294-8103
(515) 294-0467
dplazak@iastate.edu
http://www.ctre.iastate.edu/access
Research Sponsor: