A prototypical planning process is provided for developing, implementing, and evaluating public agency TDM programs that can be readily adapted and modified to fit the varied needs and circumstances of specific states or metropolitan regions. An approach is described that can be incorporated into statewide and metropolitan transportation planning processes, the development of congestion management systems, the implementation of major transportaion investment studies, and state and local ordinances. A four-step process is used to examine the feasibility of TDM program strategies that a public agency might implement. Supporting this process are specific examples from public agencies that are exhibiting the kind of analytical rigor necessary to develop an effective TDM program.

Transportation Demand Management (TDM) strategies to encourage increased use of transit, ridesharing, and other alternatives to the single-occupant automobile are being increasingly considered as an effective tool for congestion relief. However, to stimulate implementation of TDM strategies, there is a need for appropriate analysis methodologies to assess the costs and benefits of TDM strategies both to employers and to state and local policy makers. Employers, developers, and property owners need practical and easy-to-use methodologies for assessing their business decisions concerning employer-based TDM strategies. State and local agencies and employers, both public and private, who are considering implementation of a TDM program need information concerning the costs and benefits of various TDM alternatives. The public sector needs information on successful TDM experience that will aid in understanding the overall costs, benefits, and other impacts at a systemwide level of providing various public services and facilities designed to support and stimulate the implementation of TDM strategies.

Research was initially undertaken by COMSIS Corporation to (1) develop a procedure that employers, developers, and property owners (in the public and private sectors) could use to better evaluate the benefits, costs, and possible productivity gains resulting from transportation-effective, employer-based TDM strategies, and (2) provide guidance to public agencies on the systemwide costs, benefits, and other impacts of providing public services necessary to stimulate and support further implementation of TDM strategies. However, because of the unavailability of sufficient cost and effectiveness data during an employer survey process performed in early tasks of the project, revised objectives for the remaining tasks were developed. These revised objectives included the development of (1) an employer technical memorandum documenting the employer survey results and lessons learned and (2) an enhanced public agency guidance document that provides assistance to public agencies implementing TDM strategies.

Two final reports, Public Agency Guidance on Employer-Based TDM Programs and Employer Technical Memorandum: Characteristics of Effective TDM Programs have been developed; and these are available online as TCRP Web Document 22. A summary of the two reports has been published as TCRP Research Results Digest 18.