Project at a Glance

Title: A survey and analysis of employee responses to employer-sponsored trip reduction incentive programs. Final report. Appendix A: Model calibration report. Appendix B: TDM evaluation program user's guide. Appendix C: Frequencies and crosstabulations

Principal Investigator / Author(s): Schreffler, Eric N

Contractor: COMSIS Corporation

Contract Number: A932-187

Research Program Area: Emissions Monitoring & Control, Climate Change

Topic Areas: Behavioral Change, Mobile Sources & Fuels, Modeling


This summary provides a broad overview of the research conducted by COMSIS Corporation for the California Air Resources Board, entitled "A Survey and Analysis of Employee Responses to Employer-sponsored Trip Reduction Incentive Programs."

Purpose of the Research
State and Federal legislation requires most large urban areas in California to adopt Employer Trip Reduction regulations aimed at shifting commuters from solo driving to shared ride (e.g. carpooling) and alternative work arrangements (e.g. 4/40 work weeks). The overall objective of the California mandates is to reduce vehicle miles of travel (VMT) in non-attainment areas and, therefore, mobile source emissions from the automobile.

Employers are generally required to submit trip reduction plans describing a proposed program of promotional activities and incentives that would induce employees to shift to these commute alternatives, sufficient to reach a stated target.

Employers and the plan reviewers at the regulating agencies need better information and tools to help determine the most effective incentives to be offered to employees. The stated objective of the research is "to quantify the emission reduction cost effectiveness for various possible trip reduction incentives that might influence employee travel behavior in California."

To do this, information on the trip reduction effectiveness and costs of existing employer programs was collected and analyzed. From this information, a predictive software package was developed to allow employers and plan reviewers to evaluate the likely effectiveness of proposed incentive programs.

Related research has recently been performed in California and at the national level that confirms many of the ultimate findings of this research. Some specific research projects of interest involve research into the cost effectiveness of suburban employer programs in the San Francisco Bay Area (JHK, January 1993) and numerous studies of the effectiveness of programs fostered by the South Coast Air Quality Management District's Regulation XV Trip Reduction Rule.

That research (UCLA/USC, July 1992; COMSIS, October 1992; and Ernst & Young, August 1992) produced the following conclusions:

The most popular incentives offered by employers were not always the most effective.

The most effective incentives generally involved financial incentives (i.e. subsidies for using commute alternatives) or parking management (i.e. reducing the amount of parking or charging a fee).

A survey of Regulation XV sites revealed an annual program cost per employee of $105, resulting in an average trip reduction of 5-10%. A survey of 20 employer sites around the country revealed a similar cost ($118) for programs that achieved an average trip reduction of 22 %, the difference being the types of incentives offered. This led the researchers to conclude it is not necessarily ~ myth employers spend, but ~ they spend their resources.

For questions regarding this research project, including available data and progress status, contact: Research Division staff at (916) 445-0753

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