COURSE OUTLINE
Reference: CHED Memorandum Order No. 92 Se
Introduction to
Transportation
Planning and
Engineering
Prepared by:
Engr. Harold Loyd M. Ilustrisimo
Lecturer I
CE 416 – Principles of Transportation
Engineering
Introduction
Transportation is essential for a
nation’s development and growth. In both the
public and private sector, opportunities for
engineering careers in transportation are
exciting and rewarding. Elements are
constantly being added to the world’s
highway, rail, airport, and mass transit
systems, and new techniques are being
applied for operating and maintaining the
systems safely and economically. Many
organizations and agencies exist to plan,
design, build, operate, and maintain the
nation’s transportation system.
Transportation Planning
The process of transportation planning involves
the elements of situation and problem definition, search
for solutions and performance analysis, as well as
evaluation and choice of project. The process is useful
for describing the effects of a proposed transportation
alternative and for explaining the benefits to the traveler
of a new transportation system and its impacts on the
community. The highway and traffic engineer is
responsible for developing forecasts of travel demand,
conductin g e valu ation s base d on e con om ic an d
noneconomic factors, and identifying alternatives for
short-, medium-, and long-range purposes.
Basic Elements of Transportation Planning
TRANSPORTATION AND
TRAFFIC ENGINEERING
PRACTICE
Transportation
Engineering is a field or
branch of Civil Engineering
that deals with the
application of technology
and scientific principles to
the planning, functional
design, operation, and
management of facilities
for any mode of
transportation in order to
provide for the safe, rapid,
comfortable, convenient,
economical, and
environmentally
TRANSPORTATION AND
TRAFFIC ENGINEERING
PRACTICE
Traffic Engineering is that
phase of Transportation
Engineering that deals
with the planning,
geometric design, and
traffic operations of roads,
streets and highways,
their networks, terminals,
abutting lands, and
relationships with other
modes of transportation
TRANSPORTATION AND
TRAFFIC ENGINEERING
PRACTICE
In the United States,
it was in 1921 when
the title “Traffic
Engineer” was first
recognized, although
several traffic
engineering-related
activities were
already going on.
QUESTIONS:
1. To illustrate the importance of transportation
in our national life, identify a transportationrelated article that appears in a local or national
newspaper. Discuss the issue involved and
explain why the item was newsworthy.
2. How would your typical day be changed
without availability of your principal mode of
transportation? Consider both personal
transportation as well as goods and services that
you rely on.
3. Identify one significant transportation
b r e a k thr o u g h e v e n t t h a t o c c u r r e d i n t h e
Philippines. Discuss the significance of this event.
Thank You!
COURSE OUTLINE
Reference: CHED Memorandum Order No. 92 Se
Transportation
as a System
Prepared by:
Engr. Harold Loyd M. Ilustrisimo
Lecturer I
Principles of Transportation Engineering
CE 416
Introduction to
Transportation System
Transportation system consists of vehicles, roads
and highways, terminal facilities, and control
systems that move freight and passengers. These
systems are usually operated according to
established procedures and schedules in the air,
on land, and on water. The set of physical facilities,
control systems, and operating procedures
referred to as the nation’s transportation system
is not a system in the sense that each of its
components is part of a grand plan or was
developed in a conscious manner to meet a set of
specified regional or national goals and objectives.
Rather, the system has evolved over a period and
Introduction to
Transportation System
A transportation system may be
defined as consisting of the fixed
facilities, the flow entities, and the
control systems that permit people and
goods to overcome the friction of
geographical space efficiently in order
to participate in a timely manner in
some desired activity.
Components of Transportation System
A transportation
system consists of
different components
which together allow
people and goods to
overcome the
hindrance of
geography. The
different components
are:
•Fixed facilities
•Flow Entities
•Control System
Fixed
Facilities
These are the
physical
components of the
system that are
fixed in space and
constitute the
network of links
and nodes. Road,
railway track,
ocean or
waterways,
airports harbor etc.
are fixed facilities
of their respective
modes.
Flow Entities
These are the components that traverse (travel through) the fixed
facilities. They mainly include vehicles and are considered based on
shape, size, weight, acceleration and deceleration abilities. For example,
road vehicles, trains, aircraft, ships etc.
Vehicle Type and Size
Motor vehicles influence the
following:
1. Clearance for bridges,
tunnels, and grade
separation
2. Geometric design of streets,
roads, and parking lots
The design of roads and
highways still requires
information about the
minimum and maximum
dimensions of vehicles
specifically allowable weights
MOTORCYCLE
3-AXLE, 10-TIRE SINGLE UNIT
TRUCK
SEMI-TRAILER
PASSENGER
CAR
LIGHT
TRUCKS
4-AXLE, 12-TIRE SINGLE UNIT
TRUCK
FULL-TRAILER
BUS
2-AXLE, 6-TIRE SINGLE UNIT
TRUCK
TRACTOR/BOB-TAIL
RECREATIONAL VEHICLES
Control System
Vehicle Control System
• refers to the technological
way in which the vehicles
are guided either
automatically or manually.
Flow Control System
• consists of the means that
permit the efficient and
smooth operation of stream
of vehicles and the
reduction of conflicts
between them. Eg: traffic
control using traffic lights,
at the intersection, road
signs and markings, air
Forces that
Change the
Transportation
System
transportation system is in a state of equilibrium as
expressed by the traffic carried (or market share) for
each mode and the levels of service provided
(expressed as travel attributes such as time, cost,
frequency, and comfort). This equilibrium is the
result of market forces (state of the economy,
competition, costs, and prices of service),
government actions (regulation, subsidy, and
promotion), and transportation technology (speed,
capacity, range, and reliability). As these forces shift
over time, the transportation system changes as well,
creating a new set of market shares (levels of
demand) and a revised transportation system. For
this reason, the nation’s transportation system is in a
constant state of flux, causing short-term changes
due to immediate revisions in levels of service (such
as raising the tolls on a bridge or increasing the
gasoline tax) and long-term changes in lifestyles and
land-use patterns (such as moving to the suburbs
Role of
Transportation
in Society
Transportation is an inseparable part of
a society. In fact, the measure of the
development of any society is
characterized by how developed
transportation system is. Advancement
in transportation has made a vast
change in the quality of life of people.
Impact of transportation can be
summarized as below:
1.
2.
3.
4.
Economic role
Social role
Political role
Environmental role
Philippine Transportation
System
BACKGROUND
• The Philippines, a member of the Association of Southeast Asian Nations, is an archipelagic
country consisting of more than 7,100 islands. With a total land area of about 300,000 sq. km, it
has 81 provinces, 136 cities, and 1,494 municipalities (NSCB 2007). Metro Manila is the seat of the
government and the primary center of business and trade. Other urban centers include the major
cities of Cebu and Davao. The population of the Philippines is about 80 million, with a growth
rate of 2.2 percent per annum. The population density stands at 227 persons/sq. km.
• Metro Manila comprises sixteen cities and one municipality (NSCB 2007). Its land area is 636 sq.
km, and it has a population of 10.4 million. This implies that about 14 percent of the country’s
population is concentrated in only 0.3 percent of the country’s land area. Its population density is
about 16,000 persons/sq. km, one of the highest in Southeast Asia. The population growth rate is
about 3 percent, higher than the national average (ALMEC Corp. 1999).
Road Transport Network
Some 80% of domestic passenger traffic and 60% of freight traffic currently
use the road, and 75% of government expenditures on transport infrastructure goes
to road systems (Abueva 2004).
The Philippines has a total road length of about 161,000 km, with an average
road density of 0.53 km/sq. km or 2.35 km per 1,000 people. Philippine roads are
mostly made of concrete pavement. Due to heavy, overloaded trucks, pavements are
often damaged, a factor that contributes to traffic accidents. Due to a long rainy
season, floods occur throughout the Philippines, Floodwaters often cause damage to
road pavements due to inadequate drainage. There are about 11,500 bridges in the
national network (measuring about 335,500 lineal meters), of which 1,700 bridges
are temporary (DPWH 2004).
Public Transportation
The mode of public transportation in Metro Manila is predominantly
road-based, consisting largely of jeepneys and buses for primary and secondary
routes, and motorized tricycles and pedicabs for feeder routes. There are about
330 bus routes and 600 jeepney routes. These routes include those serving the
adjoining areas of Metro Manila. The jeepneys cover more than 610 km of roads
while buses operate mainly on about 350km of roads (ALMEC Corp 1999).
During rush hours, the inadequate provision of public transportation
becomes apparent. Many commuters can be seen standing on the carriageway
while waiting for buses and jeepneys. Passengers clinging to anything at the
back of jeepneys are a common sight.
Traffic Management
Traffic control devices such as
traffic signs and markings
generally follow the international
standard, the Philippines being a
signatory to the Vienna Convention
in 1968. However, many of the
signs installed conform neither to
color nor shape as provided for in
the standard. The number of traffic
signs installed is generally
insufficient. In highly urbanized
areas, these signs can hardly be
recognized, much less read, as they
compete with giant billboards in
Traffic Management
Traffic signals are commonly installed at
major intersections in many cities and towns
in the Philippines although the number is
still inadequate. Oftentimes, these signals do
not provide display phase exclusive for
pedestrians. In Metro Manila, there is a
growing concern about the safety of
pedestrians due to the closure of
intersections and with the U-turn slot
scheme replacing the control of traffic
signals. Pedestrians have practically no
opportunity to cross the road because of the
“uninterrupted” flow of traffic. Without
traffic signals controlling the traffic flow at
intersections, driving has become riskier
because of frequent swerving/weaving.
There is an urgent need to evaluate the
effectiveness of the scheme, which has the
Pedestrian Facilities
Sidewalks are in relatively good
condition; however, many
obstructions can be found on them
such as illegal vendors, electrical
posts, police outpost, etc. With the
sidewalk occupied, pedestrians
have to walk on the carriageway.
There are still very few overhead
pedestrian bridges even in Metro
Manila and at places where these
have been constructed, pedestrians
still prefer to risk their lives or
limbs by crossing the road at grade
level. Moreover, pedestrian
overpasses are often inaccessible
Vehicle Registration
The registration of vehicles in the
Philippines is handled by the Land
Transportation Office (LTO), a line agency of
the Department Transportation and
Communication (DOTC). The number of
utility vehicles or jeepneys has a share of 37
percent. The number of motorcycles has
increased tremendously in the last three
years due to the influx of cheaper models
into the country. It reached the 1.5 million
mark in 2002. However, this number
accounts for both the motorcycles (MCs) for
private use and tricycles (TCs) for public
transport use. There is therefore a need to
separate the categories since they serve
Vehicle Registration
About 40% of the total numbers
of vehicles are registered in
Metro Manila.
Motor vehicles are classified as
follows:
q Private vehicles
q For hire vehicles
q Official/Government
Insurance
• Motor vehicle owners are
re q u i r e d t o o b t a i n i n s u r a n c e
covering third-party liabilities.
The minimum insurance to be
paid to victims of traffic accidents
(fatal) was P50, 000 in 2002.
• The Insurance Surely Association
of the Philippines under the
Office of the Insurance
Commissioner accredited 112
insurance companies all over the
Philippines by 2002. It regulates
the industry to prevent the
proliferation of fly-by-night
The issuing procedure of driving
license in provided for under Republic
Act (RA) 4136.
The LTO has the full responsibility for
issuance of driving licenses. There are
three types of driving licenses:
q Student driver’s permit
q Nonprofessional driver’s license
q Professional driver’s license
Driving License
Traffic Engineering in the
Philippines
The traffic engineering practice in the
Philippines is still new. Most
intersections were previously controlled
by traffic police officers or by manually
operated traffic signals. Outside Metro
Manila, manually operated semaphore
signals displaying STOP or GO message
were installed on top of police outposts
located at the center of the intersection.
Traffic Engineering in the
Philippines
In 1977, the Traffic Engineering and
Management (TEAM) Project first
implemented an area traffic control
system in Metro Manila. It was almost at
the same period when the Traffic Control
Center, later renamed as the Traffic
Engineering Center (TEC), was
established. The center was responsible
for the implementation of various traffic
engineering and management measures
such as traffic signalization, geometric
improvement of intersections, etc.
Traffic Engineering in the
Philippines
In 1976, the Transport Training Center (TTC)
was established in the University of the
Philippines with assistance from Japan
through the Japan International Cooperation
Agency (JICA). TTC started its training
program in 1978 in the fields of traffic
engineering, transportation planning, and
traffic management for traffic law enforcers.
TTC was renamed as the National Center for
Transportation Studies and became a regular
unit of UP Diliman in 1993, with research and
support to graduate programs in the fields of
transportation engineering and
transportation planning as additional
Thank You!
COURSE OUTLINE
Reference: CHED Memorandum Order No. 92 Se
Traffic Management
Prepared by:
Engr. Harold Loyd M. Ilustrisimo
Lecturer I
CE 416 – Principles of Transportation Engineering
INTRODUCTION
Traffic management is a term used to embody the activities
undertaken by a highway transportation agency to improve roadway system
safety, efficiency and effectiveness for both providers and consumers of
transportation services. There are two distinct types of traffic management.
The first one is through the use of traditional traffic engineering tools or
simple devices to regulate and control traffic. The second relies more on
simple devices to regulate and control traffic. The second relies more on
advanced technology through the use of Intelligent Transportation Systems
(ITS). Advancement of ITS has been the primary goal of many developed
countries. The more conventional applications are common in developing
countries. However, it is not uncommon in both developed and developing
TRAFFIC REGULATIONS
Traffic regulation must cover all aspects of the control of both vehicle
(registration, ownership, mechanical fitness, accessories, size, and weight) and
driver (age, ability to operate specific types of vehicles, financial responsibility).
Traffic regulations must be reasonable and effective. This can only be
achieved through careful study. Facts must be sought through the conduct of
traffic studies, accident analysis, keeping driver records, and other data.
All traffic regulations are dependent upon the laws of the states and local
governments, especially the ordinances of cities. Legislative bodies and traffic
authorities must keep in mind that unreasonable restrictions or regulations are
not likely to last very long.
Effective Traffic Regulation
There are fundamental requirements for traffic regulation to be
effective. These are as follows:
a. Regulation should be rational.
b. Regulations should be developed progressively.
c. Regulations alone often are not enough.
Three Elements of
the Road System
ROAD/
ENVIRON
MENT
VEHICLES
DRIVER
/HUMAN
TRAFFIC CONTROL
DEVICES
There are three distinct functional groups of traffic
control devices:
a. Regulatory devices
These have the authority of law and impose
precise requirements upon the actions of the road user.
b. Warning devices
These are used to inform road users of
potentially hazardous roadway conditions or unusual
traffic movements that are not readily apparent to
passing traffic.
c. Guiding devices
These are employed simply to inform the road
user of route, destination, and other pertinent traffic.
TRAFFIC SIGNS AND
MARKINGS
Traffic signs are classified depending on
their intended uses:
a. Informative: the signs are intended
to guide users while they are
traveling.
b. Regulatory: the signs are intended to
inform users of special obligations,
restrictions, or prohibitions with which
they must comply.
c. Warning: these signs are intended to
warn users of a danger on the road and
to inform them of its nature,
Uniformity in design includes shape, color,
dimension, symbols, wording, lettering, and
illumination or reflectorization.
SHAPE
Shapes of signs are standardized as follows:
a) Equilateral triangular shape with one side
horizontal shall be used for danger warning
signs.
b) Round shape shall be used for regulating traffic.
c) Rectangular shape shall be used for informative
signs.
d) Octagonal shape shall be used for STOP signs
only.
e) Inverted equilateral triangle shall be used for
YIELD signs only.
Elements
of Design
Color
Danger warning signs shall have a yellow or
white background with black symbols and red
border.
Prohibitory signs and restrictive signs shall
have a white background with black symbols
and red border.
Mandatory signs with the exception of STOP
and YIELD signs shall have a blue background
and white symbols.
STOP signs shall have a red background and
white symbols.
YIELD signs shall have a yellow background
and red border.
Informative signs shall have a white or lightcolored symbol on a dark-colored (blue or black)
background or a blue or dark-colored symbol on
a white or light-colored background.
Elements
of Design
Size
The minimum dimensions of signs depend upon the
intended applications. Larger sizes are necessary at
wider roadways and on high speed highways.
According to section 2.5 of DPWH Highway Safety
Design Standards Part 2: Road Signs and Pavement
Markings Manual, regulatory signs are of four sizes
based on the speed of the facility as follows:
a. A for urban low-speed roads
b. B for rural roads with speed limits between 60 kph
and 70 kph
c. C for high-speed rural highways
d. D for expressways
Elements
of Design
Elements of
Design
Illumination and Reflectorization
Signs are intended to convey messages during
both daytime and night time. During hours of
darkness, this can be achieved through
illumination or by using reflective materials for
signs.
Lateral Placement
On uncurbed roads in the rural areas, the sign
should be at least 60 cm clear of the
outer edge of the road shoulder, the line of
guideposts, or face of guardrails. The clearance
should not be less than 2 m nor more than 5 m
from the edge of the travelled way, except for
large guide signs on expressways where ample
clearance may be required.
Lateral Placement
Elements of
Design
In urban areas, signs should be located away from the
face of the curb not less than
30 cm but not more than 1 m. If curb is mountable or
semi mountable, the minimum
clearance should be 50 cm. On uncurbed roads, the
distance given for rural areas shall be
used.
Height
In rural areas, the height of the sign should normally be
between 1 m and 1.5 m above the nearest edge of the
travelled way. For intersection direction signs, the height
should be increased to 2 m. Final height is dictated by
visibility factor as the sign should be mounted clear of
vegetation and it must be clearly visible under headlight
illumination at night. On curbed roads such as in urban
areas, the signs should be mounted at a minimum of 2 m
above the top of the curb to prevent obstructions to
pedestrians.
Elements of
Design
Lateral Placement and Height
Elements of
Design
Location of advance warning signs
In urban areas, warning signs should be placed
no less than 30 m but more than 100m in
advance of the hazardous area, while in rural
areas they should be placed no less than
75 m but no more than 225 m ahead of the
hazardous area. The final location shall be
determined based on the nature of the hazard,
reaction time, and operating speed in the area.
Warning Signs
The Vienna Convention allows two
forms for the warning sign – one is
triangular on shape with a red border
and the other is a diamond in shape.
Priority Signs
Priority signs have various forms. The
two most commonly used priority
signs are the STOP
and YIELD signs
Prohibition Signs
Prohibition signs are round with a red
border and either a white or a yellow
background.
Access restrictions signs can have a
red bar from low right to top left.
Parking prohibitions have a blue
background. The signs that signal the
end of a prohibition are white or
yellow with a small black border and a
black bar form left below to right top.
The bar can be replaced by a series of
small bars. In addition, the symbol for
Obligatory Signs
The obligatory signs are round and in
blue colors.
Other Prescription Signs
These signs are, in general,
rectangular with either a blue base
with a white background, or with a
light base with a dark foreground.
These signs give prohibitions,
obligations, or danger messages for
particular lanes on a multilane road.
Each lane is represented by an arrow,
to which the appropriate sign is
affixed. The background color blue is
used for major roads, white for minor
roads, and within built-up areas, and
yellow for road works.
Information Signs
These signs are rectangular with a
white or yellow plate with a symbol
that stands for the
service involved. The signs can be
either blue or green.
Direction Signs
A profusion of colors and forms is
available. In general, the forms shown
must be adopted,
and in some cases even the color
shown must be used and not be
changed.
Additional Information
These signs are small and rectangular,
they supplement the information on
the main sign
A system of clear and effective pavement
markings is essential for the guidance and control of
vehicles and pedestrians. They take the form of lines,
symbols, messages, or numerals, and may be set into the
surface of, applied upon, or attached to the pavement. In
some cases, pavement markings are used as a
supplement to other traffic control devices such as traffic
signals and road signs. In other instances, they may
simply guide traffic regulations. Pavement markings have
some definite limitations:
a. They are subject to traffic wear and require proper
maintenance.
b. They may not be clearly visible if the road is wet or
dusty (e.g., near shoulder edge or median).
c. They may be obscured by traffic.
d. Their effect on skid resistance requires careful choice of
materials.
e. They cannot be applied on unsealed roads.
Despite these limitations, they have the
advantage under favorable conditions of conveying
PAVEMENT
MARKINGS
Legal Authority
Markings shall only be applied and/or
removed by the Department of Public Works
and Highways (DPWH) or an authority to
which these powers are delegated. All linemarkings plans must be approved by the
DPWH before installation.
Standardization
As in the case with all other traffic
control devices, it is imperative that markings
be uniform so that they may be recognized
and understood instantly by all drivers.
Manuals are available from the DPWH, and on
request, it will furnish traffic authorities, road
markers, material suppliers/manufacturers, and
similarly interested agencies, detailed drawings
of the standard designs and locations.
PAVEMENT
MARKINGS
Types of Markings
Markings are classified into the following groups:
Pavement and curb markings
a. Longitudinal lines are those laid in the direction of travel.
These include Center Line, Lane Line, Double Yellow Line, “NoPassing” Zone Markings, Pavement Edge Line, Continuity Lines,
and Transition Line.
b. Transverse lines are those laid across the direction of
travel. These include Stop Line, Yield (Give Way) Lines, and
Pedestrian Crossing Markings.
c. Other lines, which include Turn Lines, Parking Bays,
Painted Median Islands, and Bus & PUJ Lane Lines.
d. Other markings, which include Approach Markings to
Islands and Obstructions, Chevron Markings, Diagonal Markings,
Types of Markings
Markings are classified into the following groups:
Object markings
a. Object within the roadway
b. Object adjacent to the roadway
Reflector markings
a. Retro-reflector raised pavement markers
b. Hazard markers
c. Delineators
Materials
Road markings should be of non-skid materials and should not
protrude more than 6 mm above the level of the carriageway.
Raised pavement markings should not protrude more than 15
mm above the level of the carriageway. The following are the
commonly used materials for road markings:
• Paint
• Thermoplastic materials
• Pre-cut sheeting
• Raised pavement markers
Color
The color of pavement markings shall be white, except for the
alternative uses of yellow in
the following cases:
a. Double yellow “no-passing” lines
b. Unbroken portion of “no-parking” lines
c. Curb markings for prohibition of parking
d. On island in line of traffic
e. Bus and PUJ lanes
Black may be used in combination with white or yellow in
hazard markers to warn drivers at locations where the protruding
objects – such as bridge piers, traffic islands, or other protruding
objects – on or near the roadway. However, the use of black does
not establish it as a standard color for pavement marking.
QUESTIONS:
1. Nowadays, many local government units
have been able to get support from private
companies in fabricating and installing traffic
signs at locations under their jurisdiction,
provided that the company’s logo or
identification is indicated in a certain area of
the sign (one-eighth to one-fifth of the total
surface area). Would you agree to this? Why
or why not?
2. Most international signs consist mainly of
symbols with minimum or almost no words
in them. Would you suggest putting words in
Tagalog or in any dialects in order to convey
their meaning? Why or why not?
Thank You!
COURSE OUTLINE
Reference: CHED Memorandum Order No.
92 Series 2017
Prepared by:
Engr. Harold Loyd Ilustrisimo
Lecturer I
CE 416 – Principles of Transportation
Engineering
Urban transportation planning involves the evaluation and selection
of highway or transit facilities to serve present and future land
uses.
The process must also consider other proposed developments and
improvements that will occur within the planning period.
Urban transportation planning is concerned with two separate time
horizons.
q implemented within a one- to
three-year period
q designed to provide better
management of existing
facilities
q involve programs such as
traffic signal timing to
improve flow, car and van
pooling to reduce congestion,
park-and-ride fringe parking
lots to increase transit
ridership, and transit
LONG-TERM
PROJECTS
deals with the long-range transportation
q
needs of an area and identifies the
projects to be constructed over a 20-year
period.
q involve programs such as adding new
highway elements, additional bus lines or
freeway lanes, rapid transit systems and
extensions, or access roads to airports or
Comprehensive Urban Area Transportation
Planning Process
COMPREHENSIVE URBAN
AREA TRANSPORTATION
PROCESS
§ Inventory of Existing Travel and Facilities
§ Establishment of Goals and Objectives
§ Generation of Alternatives
§ Estimation of Project Cost and Travel
Demand
§ Planning – Level Cost Estimation
§ Planning – Level Demand Estimation
§ Evaluation of Alternatives
§ Choice of Project
Updating Costs for a Rail Feasibility Study
The following table shows indices for 2001 and 2005 for railroads, highways,
and the Consumer Price Index. A study of a freight rail improvement project
was completed in 2001 that recommended improvements such as siding, track
extension, and track maintenance and estimated a total cost of $120 million
in 2001 dollars. The study cost $250,000 to perform, and the state agency
would like to convert this cost estimate to 2005 dollars without redoing the
entire study. How much should the improvements cost in 2005 dollars?
Updating Costs for a Rail Feasibility Study
The following table shows indices for 2001
and 2005 for railroads, highways, and the
Consumer Price Index . A study of a freight
rail improvement project was completed in
2001 that recommended improvements such as
siding, track extension, and track
maintenance and estimated a total cost of
$120 million in 2001 dollars. The study cost
$250,000 to perform, and the state agency
would like to convert this cost estimate to
2005 dollars without redoing the entire study.
How much should the improvements cost in 2005
dollars?
Suggested Readings:
Chapter 4: Route Planning
Local Public Transport Route Plan Manual
DOTR, DILG, LTFRB
Flow rate is defined as the number of vehicles passing a point during a
specified period of time.
Example:
Let us suppose a 15-minute count of
vehicles bound for Manila was
conducted at a particular location
on Quezon Avenue. A summary is shown
in the table below:
TYPE
15-MINUTE COUNT
Car / Van
420
Jeepney
300
Bus
16
Truck
28
Estimate the flow rate in vehicles per
hour.
Speed is defined as rate of motion in distance per unit time. When
describing traffic stream, two types of speed are used: time mean speed
and space mean speed.
Time Mean Speed / Spot Speed
- is simply the arithmetic mean
of the speeds of vehicles
passing a point within a given
interval of time.
Example:
The speed of 25 cars was observed.
10 cars were noted to travel at 35
kph, 8 cars at 40 kph, 2 cars at 50
kph, and 5 cars at 45 kph. Assuming
that each car was traveling at
constant speed, determine the time
mean speed.
Speed is defined as rate of motion in distance per unit time. When
describing traffic stream, two types of speed are used: time mean speed
and space mean speed.
Space Mean Speed / Harmonic Mean Speed
- is used to describe the rate of
movement of a traffic stream within a
given section of road. It is the speed
based on the average travel time of
vehicles in the stream within the
section.
Example:
The speed of 25 cars was observed.
10 cars were noted to travel at 35
kph, 8 cars at 40 kph, 2 cars at 50
kph, and 5 cars at 45 kph. Assuming
that each car was traveling at
constant speed, determine the space
mean speed.
Density is defined as the number of vehicles in a given length of road at
an instant point in time.
Time headway is defined as the time interval between passage of
consecutive vehicles at a specified point on the road with a unit of time
per vehicles.
�
Example:
�� =
�
During morning peak hour, the average
headway of UP-Katipunan jeepneys is
estimated at 5 minutes. If the
passenger demand during the same period
is 240, determine whether there is a
need to increase the number of jeepney
units (or shorten the headway) for this
route. Assume that passenger demand is
evenly distributed within that period
and the average load/occupancy is 14
passengers per jeepney. (Note: This
assumption may not necessarily be true
due to fluctuation of passenger demand
and variability of passenger
occupancy.)
Spacing is the distance between two vehicles measure from the front
bumper of a vehicle to that of another.
�
Example:
�=
�
During heavy traffic congestion, it was
observed that the average spacing of
vehicles in queue in the innermost lane
of EDSA is 6.5 m. Determine the jam
density of stopped vehicles.
It can only be measure, however, if a detector is installed at a
specific point on the carriageway. It is defined as the total time of a
detector is occupied divided by the total time of observation.
A relationship exists among the three most important traffic
variables: flow rate, space mean speed, and density. A dimensional
analysis of the units will show that flow rate (veh/hr) is simply
the product of density (veh/km) and space mean speed (km/hr), or
� = � ∙ ��
As mentioned earlier, density is the most difficult variable to measure.
It can be obtained indirectly using this relation.
Volume-speeddensity relations
for the inner lane
of South Luzon
Example:
Data on density and speed were obtained
from a four-line, two-way rural highway
(in one direction only):
DENSITY, veh/km
SPEED, kph
75
45
15
85
142
10
100
30
Determine the relation between density
and speed.
Example:
Data on density and speed were obtained
from a four-line, two-way rural highway
(in one direction only):
DENSITY, veh/km
SPEED, kph
75
45
15
85
142
10
100
30
Determine the relation between density
and speed.
Example:
Using the results of the previous
example, determine the free flow speed
and jam density.
A relationship exists among the three most important traffic
variables: flow rate, space mean speed, and density. A dimensional
analysis of the units will show that flow rate (veh/hr) is simply
the product of density (veh/km) and space mean speed (km/hr), or
� = � ∙ ��
As mentioned earlier, density is the most difficult variable to measure.
It can be obtained indirectly using this relation.
Example:
In the previous example, determine the
capacity of the rural highway in one
direction.
THANK YOU!
COURSE OUTLINE
Reference: CHED Memorandum Order No.
92 Series 2017
Introduction
to Travel
Demand
Forecasting
Prepared by:
Engr. Alyzza Elaine B. Ojeda
Lecturer I
CE 416
Principles of Transportation Engineering
Forecasting Travel Demand
❑ Travel demand is expressed as the number of
persons or vehicles per unit time that can be
expected to travel on a given segment of a
transportation system under a set of given
land-use, socioeconomic, and environmental
conditions.
❑ Forecasts of travel demand are used to establish
the vehicular volume on future or modified
transportation system alternatives.
❑ The travel demand forecasting process is as
much an art as it is a science.
The methods for forecasting travel demand can range from a simple
extrapolation of observed trends to a sophisticated computerized process
involving extensive data gathering and mathematical modeling.
Judgments are required concerning the various parameters—that is,
population, car ownership, and so forth—that provide the basis for a travel
forecast. The methods used in forecasting demand will depend on the
availability of data and on specific constraints on the project, such as
availability of funds and project schedules.
Demand Forecasting Approach
Urban Travel Demand Forecasts
❑ when first developed in the 1950s and 1960s
❑ required that extensive databases be prepared using home interview and/or roadside
interview surveys
❑ the information gathered provided useful insight concerning the characteristics of the
trip maker, the land use at each end of the trip and the mode of travel.
❑ travel data then could be aggregated by zone and/or be used at a more disaggregated
level to formulate relationships between variables and to calibrate models.
Intercity Travel Demand Forecasts
❑ data are generally aggregated to a greater extent than for urban travel forecasting, such
as city population, average city income, and travel time or travel cost between city pairs.
❑ The availability of travel data improved considerably with the formation of the Bureau of
Transportation Statistics
❑ The availability of data from the Census Bureau’s American Community Survey is
another positive development.
There are two basic demand forecasting situations in transportation planning. The first involves travel
demand studies for urban areas, and the second deals with intercity travel demand. Urban travel demand
forecasts, when first developed in the 1950s and 1960s, required that extensive databases be prepared using
home interview and/or roadside interview surveys. The information gathered provided useful insight
concerning the characteristics of the trip maker, such as age, sex, income, auto ownership, and so forth; the
land use at each end of the trip; and the mode of travel. Travel data then could be aggregated by zone
and/or be used at a more disaggregated level— that is, household or individual—to formulate relationships
between variables and to
calibrate models.
In the intercity case, data are generally aggregated to a greater extent than for urban travel forecasting, such
as city population, average city income, and travel time or travel cost between city pairs. The availability of
travel data improved considerably with the formation of the Bureau of Transportation Statistics, now within
the Research and Innovative Technology Administration (RITA) of the U.S. DOT. The availability of data from
the Census Bureau’s American Community Survey is another positive development. This chapter describes
the urban travel forecasting process. The underlying concepts may also be applied to intercity travel
demand.
The databases that were established in many urban transportation studies have been used for the
calibration and testing of models for trip generation, distribution, modal choice, and traffic assignment.
These data collection and calibration efforts involved a significant investment of money and personnel
resources, and consequent studies are based on updating the existing database and using models that had
been previously developed.
Factors Influencing
Travel Demand
❑ Land-use
Characteristics
❑ Socioeconomic
Characteristics
❑ The availability of
Transportation
Facilities and
Services “Supply”
The three factors that influence the demand for urban travel are: (1) the location and intensity of land
use; (2) the socioeconomic characteristics of people living in the area; and (3) the extent, cost,
and quality of available transportation services. These factors are incorporated in most travel
forecasting procedures.
Land-use characteristics are a primary determinant of travel demand. The amount of traffic generated
by a parcel of land depends on how the land is used. For example, shopping centers, residential
complexes, and office buildings produce different traffic generation patterns.
Socioeconomic characteristics of the people living within the city also influence the demand for
transportation. Lifestyles and values affect how people decide to use their resources for transportation.
For example, a residential area consisting primarily of high-income workers will generate more trips
by automobile per person than a residential area populated primarily by retirees.
The availability of transportation facilities and services, referred to as the supply, also affects the
demand for travel. Travelers are sensitive to the level of service provided by alternative transportation
modes. When deciding whether to travel at all or which mode to use, they consider attributes such as
travel time, cost, convenience, comfort, and safety.
Sequential
Steps for
Travel
Forecasting
Sequential
Steps for
Travel
Forecasting
Prior to the technical task of travel forecasting, the study area must be delineated into a set of
traffic analysis zones (TAZ) that form the basis for analysis of travel movements within, into,
and out of the urban area as discussed. The set of zones can be aggregated into larger units,
called districts, for certain analytical techniques or analyses that work at such levels. Land use
estimates are also developed.
Travel forecasting is solely within the domain of the transportation planner and is an integral
part of site development and traffic engineering studies as well as areawide transportation
planning. Techniques that represent the state-of-the-practice of each task are described to
introduce the topic and to illustrate how demand forecast can be determined. Variations of
each forecasting technique is described in the literature.
The approach most commonly used to forecast travel demand is based on land use and travel
characteristics that provide the basis for the “four-step process” of trip generation, trip
distribution, modal choice, and traffic assignment illustrated in the figure. Simultaneous model
structures have also been used in practice, particularly to forecast intercity travel.
Trip Generation
❑ is the process of determining the number of trips that
will begin or end in each traffic analysis zone within a
study area
❑ each trip has two ends, and these are described in
terms of trip purpose, or whether the trips are either
produced by a traffic zone or attracted to a traffic
zone
❑ Trip generation analysis has two functions:
❑ to develop a relationship between trip end
production or attraction and land use
❑ to use the relationship to estimate the number of
trips generated at some future date under a new
set of land use conditions.
Trip Generation
❑ To illustrate the process, two methods
are considered: cross-classification and
rates based on activity units. Another
commonly used method is regression
analysis, which has been applied to
estimate both productions and
attractions.
Trip generation is the process of determining the number of trips that will begin or end in each
traffic analysis zone within a study area. Since the trips are determined without regard to
destination, they are referred to as trip ends. Each trip has two ends, and these are described in
terms of trip purpose, or whether the trips are either produced by a traffic zone or attracted to
a traffic zone. For example, a home-to-work trip would be considered to have a trip end
produced in the home zone and attracted to the work zone. Trip generation analysis has two
functions:
(1)
(2)
to develop a relationship between trip end production or attraction and land use; and
to use the relationship to estimate the number of trips generated at some future date under
a new set of land use conditions. To illustrate the process, two methods are considered:
cross-classification and rates based on activity units. Another commonly used method is
regression analysis, which has been applied to estimate both productions and attractions.
This method is used infrequently because it relies on zonal aggregated data. Trip
generation methods that use a disaggregated analysis, based on individual sample units
such as persons, households, income, and vehicle units, are preferred.
❑
Cross-Classification
Cross-classification is a technique
developed by the Federal Highway
Administration (FHWA) to determine the
number of trips that begin or end at the
home. Homebased trip generation is a
useful value because it can represent a
significant proportion of all trips.
❑ The first step is to develop a relationship
between socioeconomic measures and trip
production. The two variables most
commonly used are average income and
auto ownership. Other variables that could
be considered are household size and stage
in the household life cycle. The
relationships are developed based on
income data and results of O-D surveys.
Region A is made up of zones
1, 2, 3, 4, and 5. A census was
done within the region to
determine the number of trips
per household size by auto
ownership. The data gathered
are presented in Table 4.1.
The forecasted number of
household in Zone 3 by size
and auto ownership are
presented in Table 4.2.
Solve for:
a. Trip rates by auto
ownership and household size
b. Total number of trips
generated in Zone 3
HOUSEHOLD SIZE
AUTO OWNERSHIP
0
1
2+
1
1.96
2.45
2.29
2
3.25
2.81
3.30
3+
3.20
3.04
3.58
HOUSEHOLD SIZE
AUTO OWNERSHIP
0
1
2+
1
55
319
12
2
114
518
875
3+
39
295
2012
A travel survey produced the data
shown in the table. Twenty
households were interviewed. The
table shows the number of trips
produced per day for each of the
households (numbered 1 through
20), as well as the corresponding
annual household income and the
number of automobiles owned.
Household income is classified into
three: low income (<$32,000),
medium income
(> $32,000 $48,000), and high income
(>$48,000). Solve for the trip rate
by income classification and auto
ownership in trips per household.
L
L
H
M
L
H
M
M
L
H
H
M
L
M
M
H
H
M
H
L
AUTO OWNERSHIP
0
INCOME
CLASSIFICATION
HH
1
Trips
HH
2
Trips
HH
3
Trips
HH
Trips
Low
Medium
High
AUTO OWNERSHIP
INCOME
CLASSIFICATION
0
Low
Medium
High
1
2
3
Rates Based on Activity Units
❑ The preceding section illustrated how trip
generation is determined for residential
zones where the basic unit is the
household. Trips generated at the
household end are referred to as
productions, and they are attracted to
zones for purposes such as work, shopping,
visiting friends, and medical trips. Thus, an
activity unit can be described by measures
such as square feet of floor space or
number of employees. Trip generation rates
for attraction zones can be determined
from survey data.
A commercial center in the downtown contains several retail establishments and light
industries. Employed at the center are 220 retail and 650 non-retail workers. The
employees have the following demographic:
Retail Employees - 35% home-based work, 35% home-based other and 30%
non-home-based
Non-retail Employees - 50% home-based work, 30% home-based other and 20%
non-home-based
Determine the number of trips per day attracted to this zone. Table 4.4 shows the trip
rate in trips per employee by type of work and type of employee.
NON-RETAIL EMPLOYEE
HOME-BASED WORK
HOME-BASED OTHER
NON-HOME-BASED
RETAIL EMPLOYEE
Regression Analysis
A multiple regression analysis shows the
following relationship for the number of trips
per household.
T = 0.82 + 1.3P + 2.1A
Where:
T = number of trips per household per day
P = number of persons per household
A = number of autos per household
If a particular TAZ contains 250 households
with an average of 4 persons and 2 autos for
each household, determine the average number
of trips per day in that zone.
Thank You!
COURSE OUTLINE
Reference: CHED Memorandum Order No. 92 Series 2017
Trip
Distribution
Prepared by:
Engr. Harold Loyd M. Ilustrisimo
Lecturer I
CE 416: Principles of Transportation Engineering
Trip Distribution
• is a process by which the trips generated in one zone are
allocated to other zones in the study area.
• considers internal-external trips (or vice versa) where one end
of the trip is within the study area and the other end is
outside the study area.
• several basic methods are used for trip distribution
• Gravity Model
• Growth Factor Models
Trip Distribution
🞇 Two
basic methods by whic h this c onnec tion can be achieved.
1. Growth factor method
🞇 C onstant fac tormethod
🞇 Average fac tormethod
🞇 Fratarmethod
🞇 Furness method (double constrained)
2. Synthetic M ethods
🞇 Gravitymodel
🞇 Opportunity model
Gravity Model
• The most widely used and documented trip distribution
model is the gravity model, which states that the number of
trips between two zones is directly proportional to the
number of trip attractions generated by the zone of
destination and inversely proportional to a function of
time of travel between the two zones.
Gravity Model
A survey was done on Study Zone A. The survey shows that 110 trips per day
are produced in the zone, all of them going to the three shopping centers are
located outside the zone. The shopping centers have the following
characteristics:
Shopping Center
Floor Space
(in 1000ft2)
Distance from Zone A
(in miles)
1
184
8
2
215
4
3
86
5
Assuming the floor space is the measure of attractiveness, and the value of n is
2, solve for the number of trips attracted to shopping center 1, 2, and 3.
Gravity Model
To illustrate the application of the gravity model, consider a study area consisting of three zones. The
data have been determined as follows: the number of productions and attractions has been computed
for each zone by methods described in the section on trip generation, and the average travel times
between each zone have been determined. Assume Kij = 1 for all zones. Finally, the F values have
been calibrated as previously described and are shown for each travel time increment. All necessary
information are presented on the tables below.
Time
F
Determine the number of zone-to-zone trips through two iterations.
(mins)
Zone
1
2
3
Total
1
82
Trip Production
140
330
280
750
2
52
Trip Attraction
300
270
180
Table 4.2a. Trip Productions and Attractions for a Three-Zone Study Area
750
3
50
4
41
Zone
1
2
3
5
39
1
5
2
3
6
26
2
2
6
6
7
20
3
3
6
5
8
13
Table 4.2b. Travel Time between Zones (mins)
Table 4.2c. Travel Time versus F
Gravity Model
To create a doubly constrained gravity model
where the computed attractions are identical to the
given attractions, the adjustment is done using the
formula
Growth Factor Model
• Trip distribution can also be computed when the only data available are the origins
and destinations between each zone for the current or base year and the trip
generation values for each zone for the future year. This method was widely used
when origin-destination data were available but the gravity model and calibrations
for F factors had not yet become operational. Growth factor models are used
primarily to distribute trips between zones in the study area and zones in cities
external to the study area. Since they rely upon an existing origin-destination matrix,
they cannot be used to forecast traffic between zones where no traffic currently
exists. Further, the only measure of travel friction is the amount of current travel.
Thus, the growth factor method cannot reflect changes in travel time between
zones, as does the gravity model.
Fratar Method
a mathematical formula that proportions future trip
generation estimates to each zone as a function of the
product of the current trips between the two zones
Tij and the growth factor of the attracting zone Gj.
Furness Method
EXAMPLE
EXAMPLE
EXAMPLE
EXAMPLE
EXAMPLE
EXAMPLE
Thank You!
COURSE OUTLINE
Reference: CHED Memorandum Order No.
92 Series 2017
Modal
Split
Prepared by:
Engr. Harold Loyd M. Ilustrisimo
Instructor I
CE 416: Principles of Transportation
Engineering
Types of Mode
Choice Models
q Direct Generation
Models
q Trip End Models
q Trip Interchange
Models
q Logit Models
Types of Mode
Choice Models
Transit trips can be generated directly, by estimating either total person trips
or auto driver trips. Figure 12.8 is a graph that illustrates the relationship
between transit trips per day per 1000 population and persons per acre versus
auto ownership. As density of population increases, it can be expected that
transit riding will also increase for a given level of auto ownership.
q Direct Generation
Models
q Trip End Models
q Trip Interchange
Models
q Logit Models
This method assumes that the attributes of the system are not relevant.
Factors such as travel time, cost, and convenience are not considered. These
so-called “pre-trip” distribution models apply when transit service is poor and
riders are “captive,” or when transit service is excellent, and “choice” clearly
favors transit. When highway and transit modes “compete” for auto riders,
then system factors are considered.
Types of Mode
Choice Models
q Direct Generation
Models
q Trip End Models
q Trip Interchange
Models
q Logit Models
Types of Mode
Choice Models
q Direct Generation
Models
q Trip End Models
q Trip Interchange
Models
q Logit Models
Types of Mode
Choice Models
To determine the percentage of total person or auto trips that will use transit,
estimates are made prior to the trip distribution phase based on land-use or
socioeconomic characteristics of the zone. This method does not
incorporate the quality of service.
q Direct Generation
Models
q Trip End Models
q Trip Interchange
Models
q Logit Models
The mode choice model shown in Figure 12.9 is based on two factors:
households per auto and persons per square mile. The product of these
variables is called the urban travel factor (UTF). Percentage of travel by
transit will increase in an S curve fashion as the UTF increases.
Types of Mode
Choice Models
q Direct Generation
Models
q Trip End Models
q Trip Interchange
Models
q Logit Models
Types of Mode
Choice Models
q Direct Generation
Models
q Trip End Models
q Trip Interchange
Models
q Logit Models
Types of Mode
Choice Models
q Direct Generation
Models
q Trip End Models
q Trip Interchange
Models
q Logit Models
In this method, system level-of-service variables are considered, including
relative travel time, relative travel cost, economic status of the trip maker,
and relative travel service. An example of this procedure is illustrated using
the QRS method which takes account of service parameters in estimating
mode choice. The QRS method is based on the following relationship:
Types of Mode
Choice Models
q Direct Generation
Models
q Trip End Models
q Trip Interchange
Models
q Logit Models
In-vehicle time is time spent traveling in the vehicle, and excess time is
time spent traveling but not in the vehicle, including waiting for the train or
bus and walking to the station. The impedance value is determined for
each zone pair and represents a measure of the expenditure required to
make the trip by either auto or transit. The data required for estimating
mode choice include
§ distance between zones by auto and transit
§ transit fare
§ out-of-pocket auto cost
§ parking cost
§ highway and transit speed
§ exponent values
§ median income
§ excess time, which includes the time required to walk to a
transit vehicle and time waiting or transferring.
Assume that the time worked per year is 120,000 min.
Types of Mode
Choice Models
q Direct Generation
Models
q Trip End Models
q Trip Interchange
Models
q Logit Models
Types of Mode
Choice Models
q Direct Generation
Models
q Trip End Models
q Trip Interchange
Models
q Logit Models
Types of Mode
Choice Models
q Direct Generation
Models
q Trip End Models
q Trip Interc
Models
q Logit Mode
An alternative approach used in transportation demand analysis is to consider
the relative utility of each mode as a summation of each modal attribute.
Then the choice of a mode is expressed as a probability distribution. For
example, assume that the utility of each mode is
If two modes, auto (A) and transit (T), are being considered, the probability
of selecting the auto mode A can be written as
This form is called the logit model, as
illustrated in Figure 12.10 and provides a
convenient way to compute mode choice.
Choice models are utilized within the urban
transportation planning process, in transit
marketing studies, and to directly estimate
travel demand.
ꢀ ꢁ = − 0.46ꢂ − 0.35ꢃ 1 − 0.08ꢃ 2 − 0.005ꢄ
ꢀ = − 0.07ꢂ − 0.05ꢃ − 0.15ꢃ − 0.005ꢄ
ꢃ
1
2
ꢀ ꢁ = − 0.46ꢂ − 0.35ꢃ 1 − 0.08ꢃ 2 − 0.005ꢄ
ꢀ ꢁ = − 0.46ꢂ − 0.35(20) − 0.08(8) − 0.005(320)
ꢅ ꢆ = −ꢇ.ꢈ
ꢀ ꢃ = − 0.07ꢂ − 0.05ꢃ 1 − 0.15ꢃ 2 − 0.005ꢄ
ꢀ ꢃ = − ꢂ0.07ꢂ − 0.05(30) − 0.15(6) − 0.005(100)
ꢅ ꢍ = −ꢌ.ꢇꢈ
ꢉ ꢆ =ꢊꢋ
.ꢌ%
ꢉꢍ
=ꢇꢇ .ꢂꢎꢎ %
THANK YOU!
COURSE OUTLINE
Reference: CHED Memorandum Order No. 92 Series 2017
Route / Traffic Assignment
Prepared by:
Engr. Harold Loyd M.
Ilustrisimo
Instructor I
CE 416: Principles of
Transportation Engineering
Demand Analysis: The 4-Step Model
Trip Assignment
Going to A
Using CAR:
Road Network
50% = 455 cars
Origin X
30% = 273 cars
20% = 182 cars
A
29
Destination A
◾ Purposes
◾ Testing of alternatives
◾ Establishment of short range priority programs for traffic flow
improvements
◾ Analysis of the location of transportation facilities within a
corridor
◾ Providing input to other planning tools (such as air quality
studies)
◾ Detailed study of the effects of a traffic generator on traffic
flows
◾ Requirements
◾ Network geometry
◾ N etwork parameters for each link
◾ An origin-destination matrix to be loaded
◾ Assignment rule or hypothesis
◾ Output
◾ Loads or travel volumes on each segment of
the transportation network
Traffic
Assignment
 The final step in the transportation forecasting process
is to determine the actual street and highway routes
that will be used and the number of automobiles and
buses that can be expected on each highway segment. The
procedure used to determine the expected traffic volumes
is known as traffic assignment.
 Since the numbers of trips by transit and auto that will
travel between zones are known from the previous steps
in the process, each trip O-D can be assigned to a
highway or transit route. The sum of the results for
each segment of the system results in a forecast of the
average daily or peak hour traffic volumes that will
occur on the urban transportation system that serves the
study area.
Traffic
Assignment
 To summarize, the trip generation and mode-destination
choice models give total highway traffic demand between
a specified origin (the neighborhood from which trips
originate) and a destination (the geographic area to
which trips are destined), in terms of vehicles per some
time period (usually vehicles per hour). With this
information in hand, the final step in the sequential
approach to travel demand and traffic forecasting—trip
assignment—can be addressed. The result of the route
choice decision will be traffic flow (generally in units
of vehicles per hour) on specific highway routes, which
is the desired output from the traffic forecasting
process.
User Equilibrium
 In developing theories of traveler route choice, two important assumptions are usually
made. First, it is assumed that travelers will select routes between origins and
destinations based on route travel times only (they will tend to select the route with
the shortest travel time). This assumption is not terribly restrictive, because travel
time obviously plays the dominant role in route choice; however, other, more subtle
factors that may influence route choice (scenery, pavement conditions, etc.) are not
accounted for. The second assumption is that travelers know the travel times that would
be encountered on all available routes between their origin and destination. This is
potentially a strong assumption, because a traveler may not have traveled on all
available routes between an origin and destination and may repeatedly (day after day)
choose one route based only on the perception that travel times on alternative routes are
higher.
 With these assumptions, the theory of user-equilibrium route choice can be made
operational. The rule of choice underlying user equilibrium is that travelers will select
a route to minimize their personal travel time between the origin and destination. User
equilibrium is said to exist when individual travelers cannot improve their travel times
by unilaterally changing routes.
 Stated differently [Wardrop 1952], user equilibrium can be defined as follows: “The
travel time between a specified origin and destination on all used routes is the same
and is less than or equal to the travel time that would be experienced by a traveler on
Example
 Two routes connect a city and a suburb. During the
peak-hour morning commute, a total of 4500 vehicles
travel from the suburb to the city. Route 1 has a
60-mi/h speed limit and is six miles in length;
Route 2 is three miles in length with a 45-mi/h
speed limit. Studies show that the total travel time
on Route 1 increases two minutes for every
additional 500 vehicles added. Minutes of travel
time on Route 2 increase with the square of the
number of vehicles, expressed in thousands of
vehicles per hour. Determine user-equilibrium travel
times.
Two routes connect a city and a suburb. During the peak-hour morning commute, a total of 4500 vehicles
travel from the suburb to the city. Route 1 has a 60-mi/h speed limit and is 6 miles in length; Route 2
is 3 miles in length with a 45-mi/h speed limit. Studies show that the total travel time on Route 1
increases 2 minutes for every additional 500 vehicles added. Minutes of travel time on Route 2 increase
with the square of the number of vehicles, expressed in thousands of vehicles per hour. Determine userequilibrium travel times.
Solution:
Travel time for Route 1
�1 =
Travel time for Route 2
�2 =
Two routes connect a city and a suburb. During the peak-hour morning commute, a total of 4500 vehicles
travel from the suburb to the city. Route 1 has a 60-mi/h speed limit and is 6 miles in length; Route 2
is 3 miles in length with a 45-mi/h speed limit. Studies show that the total travel time on Route 1
increases 2 minutes for every additional 500 vehicles added. Minutes of travel time on Route 2 increase
with the square of the number of vehicles, expressed in thousands of vehicles per hour. Determine userequilibrium travel times.
Solution:
Travel time for Route 1
�1 =
Travel time for Route 2
�2 =
Two routes connect a city and a suburb. During the peak-hour morning commute, a total of 4500 vehicles
travel from the suburb to the city. Route 1 has a 60-mi/h speed limit and is 6 miles in length; Route 2
is 3 miles in length with a 45-mi/h speed limit. Studies show that the total travel time on Route 1
increases 2 minutes for every additional 500 vehicles added. Minutes of travel time on Route 2 increase
with the square of the number of vehicles, expressed in thousands of vehicles per hour. Determine userequilibrium travel times.
Plotting (1) and
With Wardrop’s definition of user equilibrium, it is known that the travel times on all
(2):
used routes are equal. However, the first order of business is to determine whether both
routes are used. The figure gives a graphic representation of the two performance
functions. Note that because route 2 has a lower free-flow travel time, any total origin-todestination traffic flow less than q′ will result in only route 2 being used, because the
travel time on route 1 would be greater even if only one vehicle used it. At flows of q′
and above, route 2 is sufficiently congested, and its travel time sufficiently high, that
route 1 becomes a viable alternative.
To check if the problem’s flow of 4500 vehicles per hour exceeds q′, the following test is
conducted:
1. Assume that all traffic flow is on route 1. Substituting traffic flows of 4.5 and 0 into
the performance functions gives t1(4.5) = 24 min and t2(0) = 4 min.
2. Assume that all traffic flow is on route 2, giving t1(0) = 6 min and t2(4.5) = 24.25 min.
Thus, because t1(4.5) > t2(0) and t2(4.5) > t1(0), both routes will be used. If t1(0) had been
greater than t2(4.5), the 4500 vehicles would have been less than q′ in the figure, and
only route 2 would have been used.
Two routes connect a city and a suburb. During the peak-hour morning commute, a total of 4500 vehicles
travel from the suburb to the city. Route 1 has a 60-mi/h speed limit and is 6 miles in length; Route 2
is 3 miles in length with a 45-mi/h speed limit. Studies show that the total travel time on Route 1
increases 2 minutes for every additional 500 vehicles added. Minutes of travel time on Route 2 increase
with the square of the number of vehicles, expressed in thousands of vehicles per hour. Determine userequilibrium travel times.
Plotting (1) and
With Wardrop’s definition of user equilibrium, it is known that the travel times on all
(2):
used routes are equal. However, the first order of business is to determine whether both
routes are used. The figure gives a graphic representation of the two performance
functions. Note that because route 2 has a lower free-flow travel time, any total origin-todestination traffic flow less than q′ will result in only route 2 being used, because the
travel time on route 1 would be greater even if only one vehicle used it. At flows of q′
and above, route 2 is sufficiently congested, and its travel time sufficiently high, that
route 1 becomes a viable alternative.
To check if the problem’s flow of 4500 vehicles per hour exceeds q′, the following test is
conducted:
1. Assume that all traffic flow is on route 1. Substituting traffic flows of 4.5 and 0 into
the performance functions gives t1(4.5) = 24 min and t2(0) = 4 min.
�1 = 6 + 4�1 = 6 + 4 4.5 = 24 ���� 2. Assume that all traffic flow is on route 2, giving t1(0) = 6 min and t2(4.5) = 24.25 min.
�2 = 4 + �2 2 = 4 + 0 2 = 4 mins
Thus, because t1(4.5) > t2(0) and t2(4.5) > t1(0), both routes will be used. If t1(0) had been
2
2
�2 = 4 + �2 = 4 + 4.5 = 24.25 minsgreater than t2(4.5), the 4500 vehicles would have been less than q′ in the figure, and
�1 = 6 + 4�1 = 6 + 4 0 = 6 ����
only route 2 would have been used.
Two routes connect a city and a suburb. During the peak-hour morning commute, a total of 4500 vehicles
travel from the suburb to the city. Route 1 has a 60-mi/h speed limit and is 6 miles in length; Route 2
is 3 miles in length with a 45-mi/h speed limit. Studies show that the total travel time on Route 1
increases 2 minutes for every additional 500 vehicles added. Minutes of travel time on Route 2 increase
with the square of the number of vehicles, expressed in thousands of vehicles per hour. Determine userequilibrium travel times.
Wardrop’s User Equilibrium Definition
�1 = �2
RO UTE/TRIP ASSIGNMEN T
◾Shortest path/Minimum tree
◾ Prior to doing the all-or-nothing assignment, the shortest path
between nodes in a network must be determined
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MO O RE’S MIN IMUM RO UTE ALGO RITHM
Sample network for tree building
35
Source: Hobeika, 1991
MO O RE’S MIN IMUM RO UTE ALG O RITHM
36
Source: Hobeika, 1991
MO O RE’S MIN IMUM RO UTE ALGORITHM
18
Source: Hobeika, 1991
MO O RE’S MIN IMUM RO UTE ALGO RITHM
19
Source: Hobeika, 1991
MO O RE’S MIN IMUM RO UTE ALGO RITHM
20
Source: Hobeika, 1991
MO O RE’S MIN IMUM RO UTE ALGO RITHM
40
Source: Hobeika, 1991
MO O RE’S MIN IMUM RO UTE ALG O RITHM
22
Source: Hobeika, 1991
MO O RE’S MIN IMUM RO UTE ALGO RITHM
23
Source: Hobeika, 1991
MO O RE’S MIN IMUM RO UTE ALGORITHM
Source: Hobeika, 1991
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ALL OR NOTHING ASSIGNMENT
 Considering one OD pair, all
trips are assigned to the
shortest path from origin
to destination. After the
trips are loaded in the
network, the LOS of the roads
(or links) in the network
may change.
 Basic steps to conduct
all-or-nothing assignment:
Step 1: Find the minimum
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path between zones i and j
Thank You!