SUMMARY OF CASE STUDY EXPERIENCE
this section reviews the case studies collected and key lessons learned from the case study explorationMitigating Traffic Congestion provides over 25 in-depth case examples of demand-side programs implemented in a rich and varied range of locations, including the following:
Schools & Universities
• University of Washington - Seattle, WA
• Contra Costa County SchoolPool - CA
• Summerfest and Concert Tour - WI
• Seahawks Stadium (Qwest Field) - Seattle, WA
• Pac Bell (SBC) Park - San Francisco, CA
Recreation & Tourism Destinations
• Zion National Park - UT
• City of Aspen - CO
• Lake Tahoe Basin - CA
Transportation Corridor Planning and Construction Mitigation
• I-15 Reconstruction - Salt Lake City, UT
• I-25 & I-225 Reconstruction - Denver, CO
• Springfield Interchange - VA
Employer-Based Commute Programs
• Bal Harbour Village - FL
• CALIBRE - Alexandria, VA
• CH2M HILL - Denver, CO
• Georgia Power Company - Atlanta, GA
• Hennepin County - MN
• Johns Manville - Denver, CO
• Nike - Beaverton, OR
• Overlake Christian Church - Redmond, VA
• Simmons College - Boston, MA
• Swedish Medical Center - Seattle, WA
• Texas Children’s Hospital - Houston, TX
Location / Design Strategies
• Metropolitan Seattle Transit-Oriented Development and Flexcar - Seattle, WA
• Orenco Station Mixed-Use Development - Hillsboro, OR
• Lee County Variable Bridge Tolls - Lee County, FL
Advanced Traveler Information
• Commuter Link - Salt Lake City, UT
Demand-side programs have also been applied to major employment centers,
new development sites, airports, freight movement, and to entire regions
(via road pricing and travel reduction regulations).
This shows the diversity of applications for demand-side strategies, some focused on the traditional commuter market and others applied to school, recreation, and other types of travel. The common theme is the desire to reduce peak period travel by managing demand and removing cars from the most congested places (parking lots, roads, highways) and the most congested times. This is accomplished by facilitating efficient traveler choices of the mode of travel used, the time of departure, the route used, and by reducing the need for some trips altogether.
Another commonality is the use of demand-side strategies to address very specific problems, such as:
• Inadequate parking or road space for employees, visitors, fans, customers, etc.
• Harmful effects from automobile emissions.
• Employee tardiness or absence due to travel delays or lack of travel options.
• Recruitment and retention of skilled workers with minimal stress from commuting.
The more targeted the problem and travel market, the better chance that demand-side programs can provide an effective solution or be part of a package of solutions.
All of these problems impose a tangible cost on travelers, on business, on government, and on society as a whole. The benefit-to-cost ratio of many demand-side programs is quite high, as is discussed below.
What Works Best? A Review of International Experience
Several seminal research projects and guidance reports have been produced since the 1993 FHWA report “Implementing Effective TDM Measures” (COMSIS, 1993). This body of knowledge includes studies performed at the regional, state, national and international levels. Considerable research has been performed in U.S. regions that require employer trip reduction programs (e.g., WA and AZ); in states that embrace TDM (e.g., Florida); among research organizations (e.g., TRB and TCRP); and federal agencies (FHWA, FTA, EPA). Among the more important recent references is the TCRP Report 95, the “Traveler Response to Transportation System Changes,” which documents the impacts of various demand management strategies in chapters covering: HOV facilities, vanpools, pricing, parking management, and employer TDM (R.H. Pratt Consultant, 2003).
An example of this research comes from another TCRP project, B-4, “Cost
Effectiveness of TDM Programs,” that evaluated some 50 employer-based
demand management programs in the U.S., but provides insight into demand
management effectiveness in both commute and non-commute applications.
The study estimated that the average reduction in vehicle trips among
all these “successful” programs was 15.3% (at a cost of
about $0.75 per trip reduced). However, programs that focused on information/promotion
alone exhibited no measurable decrease in trips. Programs that provided
enhanced alternatives, such as vanpools or shuttle buses, realized a
8.5% reduction in trips. Programs that focused on financial incentives
and disincentives realized a 16.4% reduction of trips and programs that
combined enhanced alternatives with incentives/disincentives for their
use, realized a 24.5% reduction in vehicle trips. (COMSIS, 1994).
Evidence also suggests that the number of strategies implemented, or the size of the budget, does not positively correlate with higher effectiveness. Some of the simplest, albeit politically controversial, measures involve pricing of automobile travel and subsidies for high occupancy modes. So, one researcher concluded: “It’s more what you do to influence commute behavior (the strategies/incentive utilized), more than how you market the program or how much you spend” (ESTC, 1998).
Another important study, the Congressionally-mandated review of the Congestion Mitigation Air Quality (CMAQ) federal funding program performed by the Transportation Research Board, revealed that four of the five most cost-effective strategies (measured as the cost per pound of emissions reduced) funded by CMAQ were demand-side strategies, including: regional rideshare programs, charges and fees for drivers, vanpool programs, and “miscellaneous TDM” programs, (TRB 2002).
Many other recent research projects have documented the effectiveness of TDM strategies to reduce automobile travel for school trips, recreation and special event trips. This was accomplished by increasing auto occupancy (which is already higher than work travel) and providing quality shuttle service and traveler information.
The scope of demand-side strategies has evolved over the past 30 years in the U.S. However, these measures (referred to as Mobility Management in Europe and some other regions of the world) are a growing phenomenon in other countries and are even integrated into national policy in places like:
• Sweden. Where a region must consider demand management solutions before considered new road capacity.
• The Netherlands. Where travel reduction goals have been set and TDM is an integral part of the program to meet these goals.
• United Kingdom. Where all regions are required to have “green travel plan” capabilities and integrate TDM into land development approvals (AMOR, 2003).
Many other innovative applications of demand-side strategies have been tested, evaluated, and documented in Europe, Australia, Canada, etc. In Europe especially, demand-side strategies are being applied to non-commute travel markets (tourists, schools, special events) in a conscious effort to address the growth in automobile use that is affecting most countries of the world. The E.U.–funded project MOST (MObility STrategies for the next decades) provides comprehensive findings from over 30 pilot projects (AMOR 2003). A recent study by the Organization of Economic Cooperation and Development (OECD), “Road Travel Demand: Meeting the Challenge,” documents world-wide experience with demand management strategies (OECD, 2002). The resource section of this report provides references and links to related websites.
LESSONS LEARNED FROM THE CASE STUDIES
all the research on, and experience with, demand-side programs and
strategies cannot possibly be summarized in 10 brief points. However,
a few common findings and lessons can be offered here
1. Demand-Side Strategies Are About Choices –
As the term implies, demand-side strategies intend to modulate the demand
for travel in a way that is based on choices (mode, time, route, etc.),
and incentives for using alternatives to driving alone and avoiding
the most congested conditions. A good example of this is the I-15 FasTrak
program in San Diego, which allows solo drivers to pay to use the HOV
lanes and allows those sharing a ride to use the lanes for free, but
does not force a fee on any driver or require anyone to use a particular
facility (OECD, 2002).
2. Time and Financial Incentives Are Most Effective – Time savings for alternative mode users (such as HOV lanes), financial incentives (such as vanpool subsidies or tax incentives) and financial disincentives (such as parking or road pricing) are consistently cited as the most effective demand-side strategies. These intervening influences help to balance out the perceived convenience and speed of driving alone (ITE, forthcoming).
3. Incentives and Disincentives Require Good Alternatives – Time and financial incentives and disincentives are most effective when they support good travel alternatives, such as transit service, vanpool formation, carpool matching, bicycle facilities, etc. The TCRP B-4 study, cited earlier, provides tangible evidence of this symbiosis by showing that the most effective programs combined financial incentives (such as transit subsidies) with improved alternatives (such as more frequent and convenient bus service (COMSIS, 1994).
4. Managing Demand Can Be a Cost-Effective Tool – Many studies that have compared mobility and air quality strategies have concluded that demand management strategies are among the most cost-effective in that they can reduce a trip, mile of travel or ton of emissions for a relatively modest amount of money. Demand-side strategies may not be the primary solution to these problems, but if they are applied in the right situation, they can help address traffic and air pollution problems in modest, yet very affordable ways (TRB, 2002).
5. Information Technology Enhances Demand-Side Programs – While incentives and disincentives are perhaps the key to effectiveness, much of managing demand relies on good information about travel conditions and alternatives. Advances in information technology make managing demand more effective by providing real-time, accurate information on travel options, traffic conditions, alternative routes, and even dynamic matching of travelers into shared ride arrangements.
6. The Implementing Organization Should Match the Scope of the Strategies – The organizational home for demand-side programs should match the scope of the application. For example, strategies to reduce congestion around employment centers or in corridors might be managed by Transportation Management Associations, whereas regional traveler information and ridematching services might better be implemented by regional agencies with access to appropriate resources and information. Multiple organizations are often involved in a given urban area, calling for coordination and cooperation to maximize impacts.
7. Packaging Demand-Side Strategies Can Create Synergies – Research indicates that the greatest potential for demand management lies in strategic grouping of measures into “programs” of reinforcing actions. For example, limiting parking in a high-density commercial development served by convenient, reliable transit can do more to reduce vehicle trips than can solely limiting parking supply (ITE, forthcoming). One study concluded that “packaged, complementary solutions are usually more effective than a single measure” (OECD, 2002).
8. Expectations Need to Be Realistic – Demand-side programs are not a panacea for all social ills or a cure-all for traffic congestion problems. However, they can have a significant impact on travel. If the correct incentives and disincentives are used to facilitate shifts to alternative modes, demand-side strategies can reduce vehicle trips and VMT 10%-20%. Most decision-makers, however, are reluctant to adopt certain disincentives (such as parking pricing) to change travel behavior in a significant way. In the absence of these strategies, most demand management programs should only be expected to reduce travel by 0% - 5% (COMSIS, 1993). At the same time, it is important to recognize that the goals for demand-side programs often extend beyond reducing VMT to include mobility, accessibility, environmental, and other outcomes.
9. Plans for Managing Demand Should Be Integrated into Overall Transportation Plans – Demand-side strategies should be considered a set of measures to better manage existing infrastructure, but they still need to be well-planned. Demand management actions should be considered simultaneously with related transit, traffic engineering, and land use plans (ITE, forthcoming). Since many metropolitan planning organizations and regional councils now fund and oversee demand management efforts, it is important to integrate demand-side strategies into long-range plans, as well as shorter-term management and operations actions. It is also important to evaluate the impacts of actual demand-side measures, as implemented, to better inform future decision-making.
10. Demand-Side Strategies Are Practical – Demand-side strategies are compatible with sustainability, transportation-land use interaction, and other longer-term goals. Yet, it is most applicable to managing demand for finite travel markets, to solve real problem that provide tangible benefits to users and implementers. Travels are smart consumers and, when faced with tangible changes in out-of-pocket costs and travel time, will change their travel behavior in immediate and significant ways (ESTC, 2003).