Data Collection and Surveys


TDM Encyclopedia

Victoria Transport Policy Institute


Updated 30 May 2012

This chapter discusses how to collect data and perform surveys for TDM program planning and evaluation.




Data Collection and Surveys are important for TDM Planning and Evaluation. This information helps improve the effectiveness of TDM programs, and identify possible problems and opportunities for improvement.


The following data is typically collected:


·         Before-and-after travel behavior data, such as commute mode choice and Average Vehicle Ridership.


·         Information on takeback effects, such as additional vehicle trips that participants make when they telecommute, or when they have extra non-work days due to Compressed Workweeks.


·         Participants’ reactions, including both positive and negative feelings about the program and individual strategies.


·         Problems and barriers, including unanticipated costs, spillover impacts (such as parking problems in nearby neighborhoods), and opposition by some participants.


·         Costs to participants, such as additional home heating and electricity consumption while telecommuting, and perceived benefits, such as more convenient childcare scheduling.


·         Costs and benefits to employers, including program administrative costs, and effects on productivity and recruitment.


·         Market information (i.e., surveys of potential participants) to help determine Demand for potential new transportation services and the effects of possible transportation improvements, and to identify barriers and potential problems.


·         Parking and traffic counts.



This information can be used to produce an annual “State of the Commute” report, which describes TDM programs and resources, travel trends, and comparisons with other communities.


Data Collection and Surveys can be performed by a regional planning agency, a TDM Program, Transportation Management Association or a Commute Trip Reduction Program.


It is important that the data which is collected be comparable between different times and geographic areas. For example, it is helpful to use the same survey questions and evaluation methods for different worksites, and when performing surveys at different times, so the results are comparable. State, provincial or regional transportation planning agencies can develop standard evaluation procedures to insure data quality and consistency.


TDM Performance Indicators

Below are common Performance Indicators used to Evaluate TDM programs. These indicators can be defined for a particular time (such as peak-hour) and geographic location (such as a particular destination, district or region).


·         Awareness – the portion of potential users who are aware of a program or service.


·         Participation – the number of people who respond to an outreach effort or request to participate in a program.


·         Utilization – the number of people who use a service or alternative mode.


·         Mode split – the portion of travelers who use each transportation mode.


·         Mode shift – the number or portion of automobile trips shifted to other modes.


·         Average Vehicle Occupancy (AVO): Number of people traveling in private vehicles divided by the number of private vehicle trips. This excludes transit vehicle users and walkers.


·         Average Vehicle Ridership (AVR): All person trips divided by the number of private vehicle trips. This includes transit vehicle users and walkers.


·         Vehicle Trips or Peak Period Vehicle Trips: The total number of private vehicles arriving at a destination (often called “trip generation” by engineers).


·         Vehicle Trip Reduction – the number or percentage of automobiles removed from traffic.


·         Vehicle Miles of Travel (VTM) Reduced – the number of trips reduced times average trip length.


·         Energy and emission reductions – these are calculated by multiplying VMT reductions times average vehicle energy consumption and emission rates.


·         Cost Per Unit of Reduction – these measures of cost-effectiveness are calculated by dividing program costs by a unit of change. For example, the cost effectiveness of various TDM programs could be compared based on cents per trip reduced, or ton of air pollution emission reductions. However, cost-effectiveness analysis that only considers direct impacts and a single objective may overlook additional costs and benefits to participants and society. For example, two TDM programs may have the same direct costs per unit of emission reduction, but differ significantly in terms of consumer costs, consumer travel options, traffic congestion, parking costs, crash risk and land use impacts.



Evaluation studies can compare Performance Indicator values before-and-after, over time (for example, over months or years), with-and-without (for example, comparing performance indicators at a worksite or area that has a TDM program with otherwise comparable sites that do not have such programs, or with regional averages).


A variety of methods can be used to collect the data needed for performance evaluation, including general travel surveys and Statistics, participant surveys, parking lot counts, traffic counts, and focus groups. Before-and-after and with-and-with comparisons require the collection of good baseline data, or the use of readily-available statistics.



Benefits and Costs

Benefits include improved TDM program effectiveness, early detection of possible problems, and justification for TDM program support.


Costs include administrative costs for gathering and evaluating information, and time/bother to participants for filling out surveys. Some employees may be uncomfortable answering surveys they consider personal or coercive.



Best Practices


·         Establish data collection and evaluation plans early during TDM program development.


·         Develop a comprehensive evaluation framework that considers direct and indirect impacts.


·         Develop baseline data, if possible, before the program is implemented.


·         Survey TDM program participants regularly (annually or semi-annually) to measure program effectiveness and identify possible problems.


·         Provide convenient opportunities for participants and other stakeholders affected by VTR programs to provide feedback by telephone, comment forms and email.


·         Have data collection plans reviewed by program evaluation experts. Review survey forms to insure that they are easily understood.


·         Perform market surveys (i.e., of potential participants) to determine Demand for alternative transportation, and identify barriers and problems that limit their use.



Wit and Humor

A doctor explains to his patient, “No wonder you feel run down, Mr. Grover. We’ve done an extensive series of tests.”



Examples and Case Studies


Washington State Commute Trip Reduction Program (

The Washington State Commute Trip Reduction law provides several possible methods for employers to track their employees’ commute trips, including participant surveys, transit pass and ridesharing benefits, or parking lot counts. The state provides a model survey, or employers can produce their own.



Web-Based Travel Surveys

Commute Trip Reduction programs in Southern California use Internet-based surveys to collect travel data from program participants. Surveys for multiple worksites can be set up and monitored from a single location. This allows data to be collected with minimal effort by both program managers and participants. Surveys are automatically cross-checked for completion, and reports are automatically generated. The results are accurate and consistent, facilitating comparisons between programs. Electronic reporting minimizes the paperwork burden required to collect accurate data.



Internet Based Surveys

Many TDM organizations now use Internet-based surveys for evaluation, some based on third-party support services. Examples include: (

Perseus (

Self Surveys (



RideLinks (

Los Angeles-based RideLinks, Inc. offers a customizable Web-based employee commute survey that requires no installation or training. From a remote location (i.e. your office in N.Y. or our office in L.A.), you can implement the survey at multiple sites (e.g. agency, employers, homes) and monitor survey progress at each site in real-time. The online survey may be supplemented if necessary with paper surveys as well.


The standard commute survey can be tailored for specific trip reduction ordinances. The Average Vehicle Ridership is automatically calculated and converted into mobile source emissions generated: CO, VOC, NOx. The report is complete the same day the survey is closed. A demonstration survey is available at their website (click on “Demo”- marked  with the blue-checked racing flags).



Travel Options Manual (

Portions of the section on Employee Trip Reduction program tracking and evaluation from the BC Transit Travel Options Manual are included below.


What is program tracking and evaluation?

Program tracking and evaluation allows you to determine how well your trip reduction efforts are doing in relation to your planned targets and in relation to other organization’s Travel Option Plan programs. Keep in mind that not meeting your targets does not always equate with failure. You may have set your goals unrealistically high, or some facet of your plan may be inappropriate to employees’ needs.


Why is ongoing evaluation important to program success?

The process of program assessment or evaluation, really takes place to some degree throughout the whole process; it is an integral part of the process. Recall in our learning cycle of “think”, “act”, “assess” and “reflect”, we learn best when theory is combined with practice.


Evaluation is where you, as a Travel Option Coordinator, and your organization as a whole, have an opportunity to learn from your experience as it grows. Viewed in this light, program evaluation, though often viewed as separate from the main stream of program activity, is in fact a very important element to long-term program success. Evaluation is the first step in the feedback loop that sees your program ‘learn’ and adapt even as it is being designed and implemented.


How often do I “reflect” on changing patterns?

Measure as often as you require to keep interest up and to track progress. People are always interested to see evidence of success or failure. This feedback in important for program profile.

Annual survey

As a minimum, an annual partial Employee Transportation Survey is an essential part of your program tracking and evaluation. Seek out enough information to compare each year’s Average Vehicle Ridership and Employee Percentage Participation with the year previous, as well as any other participation targets you may have set. Comparing data generated each year will provide a clear picture of how your Travel Option Plan is encouraging change in commuting habits.


Employee Interviews

An essential companion to the annual employee survey, are informal, but semi structured interviews with both participating and non-participation fellow employees. Semi structured interviews are just interviews with open questions that you ask of each interviewee. Open questions are used to encourage interview participants to volunteer information that you may not have anticipated in your questions. Open questions are questions for which there is no yes or no answer. For example, “How would you describe your experience as a vanpool participant?” is an open question. This will elicit more information than closed questions such as, “Was your experience with the van pool good or bad?”


Ongoing feedback

Canvass fellow workers about their expectations and concerns about your company’s Travel Option Plan. Speak with them in the lunchroom, place a more comprehensive questionnaire in the employee newsletter and (of course) bring up the topic among your own carpool mates. Keep a record of what they tell you, to see if any pattern emerges. The best suggestions usually come from those who have to live the plan, day in and day out.


What benchmarks or other measures do I use?

Average Vehicle Ridership

Average Vehicle Ridership is recommended as the best single overall benchmark for your organization. When determined using the standards of this manual, AVR is easily measured, easily understood, and will enable you to compare your commuting patterns with that of other organizations as well.


Employee Percentage Participation Calculation

We also recommend you measure and set targets using the “Employee Percentage Participation Calculation” described in this manual. This calculation measures the alternative travel modes used by employees as a percent of all employees. By using the Employee Percentage Participation Calculation, you be able to assess, report and set new targets about what percent of all employees in your workplace travel to work in the different modes i.e. solo drivers, car and van poolers, transit riders, cyclists, walker/joggers, and telecommuters.


Made-at-home benchmarks and measures

Depending on the nature of your Travel Option Plan, the travel options best suited to your organization and the targets your Travel Option Plan set, you will likely develop your own specific benchmarks to assess progress. These could include cost benefit analyzes, changing employee perception and attitudes, or trace links between the program and workplace productivity and employee absenteeism, for example.



Related Chapters

Surveys are used to Measure and Evaluate TDM programs, particularly Commute Trip Reduction and Campus Transport Management programs. Their results can be compared with other Transportation Statistics.



References And Resources For More Information


Association for Commuter Transportation ( is a non-profit organization supporting TDM Programs.


Auditor General (2003), “Road Transportation in Urban Areas: Accountability for Reducing Greenhouse Gases,” 2003 Report of the Commissioner of the Environment and Sustainable Development, Office of the Auditor General of Canada (


Bureau of Transportation Statistics ( provides information on survey methodologies.


Center for Urban Transportation Research ( provides TDM materials and classes and publishes TMA Clearinghouse Quarterly.


Lori Diggins, Eric N. Schreffler and Jennifer Gregory (2004), “Methodology for Regional Survey to Estimate Extent of Alternative Mode Switching from Voluntary Mobile Emissions Reduction Program,” Transportation Research Record 1864, TRB (, pp. 144-152.


Carolyn Fallon (2004), Charles Sullivan and David A. Hensher, “Constraints Affecting Mode Choices By Morning Car Commuters,” Transport Policy, Vol. 11, No. 1 (, January 2004, pp. 17-29.


Ann Forsyth, Kevin J. Krizek and Asha Weinstein Agrawal (2010), Measuring Walking and Cycling Using the PABS (Pedestrian and Bicycling Survey) Approach: A Low-Cost Survey Method for Local Communities, Mineta Transportation Institute, San Jose State University (; at


Sara J. Hendricks and Nevine Labib Georggi (2007), “Documented Impact of Transportation Demand Management Programs Through the Case Study Method,” Journal of Public Transportation, Vol. 10, No. 4 (, pp. 79-98.


FHWA (2000), Transportation Performance Measures Toolbox, Operations Unit, Federal Highway Administration (; at


ITE (2009), Before-And-After Study Technical Brief, Institute of Transportation Engineers (; at


Todd Litman (2010), Short and Sweet: Analysis of Shorter Trips Using National Personal Travel Survey Data, VTPI (; at


Todd Litman (2011), “Adjusting Data Collection Methods: Making the Case for Policy Changes to Build Healthy Communities,” From Inspiration to Action: Implementing Projects to Support Active Living, American Association for Retired Persons ( and Walkable and Livable Communities Institute (, pp. 104-107; at


METRO (2002), Regional TDM Program Evaluation Report, Portland METRO ( This is an example of comprehensive TDM program evaluation.


MWCG (2009), Transportation Emission Reduction (TERM) Analysis Report, Metropolitan Washington Council of Governments (; at


NZTA (2010), Kilometres Travelled And Vehicle Occupancy In Urban Areas: Improving Evaluation And Monitoring, Research Report 399, NZ Transport Agency (; at


PCT (2011), Measuring Transportation Investments: The Road To Results, Pew Charitable Trusts and The Rockefeller Foundation (; at


Performance Measurement Exchange (, is a website supported by the U.S. Federal Highway Administration and the Transportation Research Board to promote better transportation decision-making.


Lee Pike (2011), Generation Of Walking, Cycling And Public Transport Trips: Pilot Study, New Zealand Transport Agency (; at


Craig Jesus Poulenez-Donovan and Cy Ulberg (1995), Seeing the Trees and Missing the Forest: Qualitative Versus Quantitative Research Findings in a Model Transportation Demand Management Program Evaluation, Transportation Research Record 1459, TRB ( pp. 1-6.


RIDES (various years), Commute Profile, The Metropolitan Transportation Commission’s Regional Rideshare Program (


Peter R. Stopher and Stephen P. Greaves (2007), “Household Travel Surveys: Where Are We Going?,” Transportation Research A, Vol. 41, Issue 5 (, June 2007, pp. 367-381.


TravelSmart Survey Methods Website ( provides information on the survey methods used to evaluate the Australian Travel Smart programs.


TRB (2001), Performance Measures to Improve Transportation Systems and Agency Operations, Transportation Research Board (; at


TC (2002), Commuter Options: A Complete Guide for Canadian Employers, Transport Canada (


TC (2009), Canadian Guidelines for the Measurement of Transportation Demand Management Initiatives User's Guide, Transport Canada (; at


USDOT (2003), Commuter Choice Primer: An Employee's Guide to Implementing Effective Commuter Choice Programs, US Department of Transportation (


WSDOT (1999), Employee Transportation Coordinator Handbook, Washington State CTR Program (; at

This Encyclopedia is produced by the Victoria Transport Policy Institute to help improve understanding of Transportation Demand Management. It is an ongoing project. Please send us your comments and suggestions for improvement.




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