Transportation Demand Management (TDM) Transportation Demand Management (TDM) is a term applied to a broad range of strategies that are primarily intended to reduce and reshape demand (use) of the transportation systems. The information below is provided courtesy of the Washington State Department of Transportation (WSDOT) and YVCOG. What Is Transportation Demand Management? TDM and Commute Trip Reduction (CTR) Legislation TDM Strategies
top of page	What is TDM? Transportation Demand Management (TDM) is a term applied to a broad range of strategies that are primarily intended to reduce and reshape demand (use) of the transportation system. As used here, TDM means demand-side strategies (as opposed to supply-side strategies such as new lane construction) which are intended to affect how, if, and when the transportation system is used. Some of these strategies also contain elements of Transportation Systems Management (TSM), which are strategies implemented to maximize efficient operations of the transportation system. Some TDM measures have been in use for years, such as the promotion of carpooling, which began during World War II. Broader implementation of TDM began during the 1970s and 1980s, often stimulated by problems related to our heavy reliance on foreign energy sources. More recently, increasing congestion, decreasing state and federal transportation funding, and concerns over related issues such as air quality have resulted in increasing attention to TDM as an alternative to building more roads and highways.
top of page	TDM and Commute Trip Reduction (CTR) Legislation Have you ever noticed that most of the automobiles on our highways have only one person in them, and that's the driver! As more and more people begin to drive, we are beginning to see an increase in air pollution and traffic congestion. The Washington State Legislature is aware of these two problems, and in an effort to reduce air pollution, traffic congestion and energy consumption, they passed the Commute Trip Reduction (CTR) Law. This law is a Transportation Demand Management (TDM) measure that requires the State's largest counties, and cities within those counties, to develop and adopt CTR Plans by ordinances. These plans require major (affected) employers (those with over one-hundred employees) to implement programs aimed at reducing the number of single-occupant vehicle (SOV) commute trips made by their employees to the worksite. Yakima County, one of Washington's most populous counties, and the cities of Yakima, Selah, Union Gap, Toppenish and the Unincorporated County, adopted CTR Plans for their communities. YVCOG was appointed by the county and many of these cities to administer their CTR Plans. These plans set SOV reduction goals (15% by 1995, 20% by 1997, 25% by 1999, and 35% by 2005). Each affected employer has an Employee Transportation Coordinator (ETC) at the worksite. The ETC is responsible for administrating the employer's CTR program.
top of page	TDM Strategies The most obvious transportation demand strategies are those that change the way we travel to work. The first thing that many people think of is car pooling or van pooling. But don't forget other commute modes such as walking, bicycling, or public transportation. Two less obvious transportation demand strategies are those that change the way we work. Telecommuting is when the employee works from home on one or more days a week. Alternative work schedules allow the employee to complete the "regular" work hours in less than the traditional 5 days. Return to Top of Page | Home Last update 7/25/07