Travel Demand Management:
An Introduction
CIVITAS Open Academy
Ljubljana
15 April 2010
Eric N. Schreffler
Transport Consultant
San Diego, California, USA
Two Approaches

Supply-oriented:
predict need, supply
infrastructure to
meet travel demand

Demand-oriented:
influence the need
to, timing of, and
location of travel to
reduce overall
demand and make
existing supply more
efficient
TDM Basics - Ljubljana Workshop
Outline

What is TDM?

Why and how can we manage demand?

TDM and infrastructure

TDM cost effectiveness

Final thoughts

Source of more information
TDM Basics - Ljubljana Workshop
V/C Ratio – Volume/Capacity
Predict and Provide Demand Management
V – predict demand
V – manage demand
---
---
C – provide capacity
C – maximize efficiency
Assumes volume
constant and adjusts
capacity
Assumes capacity
constant and adjusts
demand
TDM Basics - Ljubljana Workshop
DEFINITION: What is
Travel Demand Management?
The U.S. Department of Transportation,
Federal Highway Administration defines TDM:
Managing travel demand is about providing
travelers, regardless of whether they drive
alone, with travel choices, such as work
location, route, time of travel and mode. In
the broadest sense, “demand management
is defined as providing travelers with
effective choices to improve travel
reliability.”
Federal Highway Administration, 2006
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TRAVEL DEMAND vs.
TRAFFIC MANAGEMENT
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Other Definitions of TDM

“balancing travel needs with the capacity of
available facilities to efficiently handle this
demand”

or “application of strategies & policies to
reduce automobile travel demand, or to
redistribute this demand in space or in time””[
TDM Basics - Ljubljana Workshop
DEFINITION: TDM
City Perspective

Any strategy, program, or combination of
strategies and programs designed to
change travel habits. Specifically, TDM
projects attempt to reduce single
occupant vehicle trips.
(Greenfield, Massachusetts)

The general term for strategies that result
in more efficient use of transportation
resources. (Burlington, Vermont)
TDM Basics - Ljubljana Workshop
TDM vs. Mobility Management

Transportation Demand Management (TDM)
tends to include a broad set of strategies that
includes road pricing, facilities to encourage mode
shift, and incentives to use them

Mobility Management (MM) may be seen as a
subset of TDM which includes measures such as
information, marketing, partnerships,
communications, and promotion of sustainable
modes. “MM is soft measures to influence travel
before it starts.”
TDM Basics - Ljubljana Workshop
Sustainable Urban Transport
The European Union (Council of Ministers of
Transport) defines a sustainable transportation
system as one that…
allows the basic access and development
needs of individuals, companies and
society to be met safely and in a manner
consistent with human and ecosystem
health, and promotes equity within and
between successive generations.
TDM Basics - Ljubljana Workshop
Why Manage Demand?

Cannot build our way out of congestion

Negative impacts of car of environment

It is much cheaper than new infrastructure

It makes better use of existing system

Makes road investment last longer

People appreciate having choices

People want a sustainable future
TDM Basics - Ljubljana Workshop
Categories of TDM Strategies

Enhanced travel options

New Public/Private Partnerships

Financial Incentives and disincentives

Real-time Traveler Information

Access and parking management
TDM Basics - Ljubljana Workshop
TDM Strategies: A Sample

Travel plans at worksites and schools

Personalized travel planning and advice

Carpool ride matching services

Promotion of public transport services

Offer of incentives to use sustainable modes

Priority treatment of high-occupancy vehicles

Managing parking and parking pricing
TDM Basics - Ljubljana Workshop
TDM Applications

Schools & Universities

Special Events

Recreation & Tourism Destinations

Transportation Corridor Planning &
Construction Mitigation

Employer-Based Commute Programs

Airports

Incidents & Emergencies

Freight Transportation
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Integration with Infrastructure

TDM can influence demand before decision
made to use car on highway

Mode choice is only one response, time and
route choice can influence efficiency of
congested roads

Preference can be given to high occupancy
vehicles

TDM strategies can be tested during
construction activities
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Integration

TDM can be seen as part of daily
management and operation of road system

Traffic management centers can influence
choices

Incentives and disincentives can be offered
to provide time advantages to higher
occupant modes

Focus is on traveler rather than on vehicle
TDM Basics - Ljubljana Workshop
Benefits of TDM

TDM makes road system more efficient

TDM is good for business

TDM is a low-cost solution

Effective TDM addresses many urban goals:
• Congestion relief
• Mobility enhancement
• Air quality abatement
• Energy conservation
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Comparative Cost Effectiveness
Los Angeles County
Performance Monitoring Study
Carpool program removed car from the roads
for about $1 per day
New tram line costs about $2.50 per day for
each new rider (and not all from cars)
TDM Basics - Ljubljana Workshop
TDM Strategies and Emissions
Comparative Cost Effectiveness
(cost per pound of emissions reduced)

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Regional rideshare programs .............................................
Charges and fees ................................................................
Vanpool programs..............................................................
Miscellaneous TDM...........................................................
Conventional fuel bus replacement....................................
Alternative fuel vehicles ....................................................
Traffic signalization ........................................................
Employer trip reduction ...................................................
Conventional transit service upgrades .............................
Park-and-ride lots (rideshare and transit).........................
Modal subsidies and vouchers .........................................
New transit capital systems/vehicles ...............................
Bicycle and pedestrian programs .....................................
Shuttles and feeder buses ………….......................................
Freeway/incident management ........................................
Alternative fuel buses ......................................................
TDM Basics - Ljubljana Workshop
$3.70/lb.
$5.15/lb.
$5.25/lb.
$6.25/lb.
$8.05/lb.
$8.09/lb.
$10.05/lb.
$11.35/lb.
$12.30/lb.
$21.50/lb.
$23.30/lb.
$33.20/lb.
$42.05/lb.
$43.75/lb.
$51.20/lb.
$63.20/lb.
Final Thoughts

TDM is not a cure-all; one tool in toolbox

TDM involves packages of strategies
designed to influence travel and travelers

Individual strategies have finite impacts

TDM most effective when integrated

TDM is widely acknowledged as low-cost
when compared to supply-side solutions

TDM is becoming more of a philosophy
than a set of strategies
TDM Basics - Ljubljana Workshop
ADDITIONAL INFORMATION
U.S. Perspective on European TDM
http://international.fhwa.dot.gov/traveldemand/index.cfm
www.eltis.org
TDM Encyclopedia
WWW.VTPI.ORG/TDM
TDM Basics - Ljubljana Workshop