Transport Demand Management - TDM (also referred to as "Travel Demand Management") comprises a set of policies, strategies and action plans designed to change and reduce demand for car use through changes in travel behaviour.
Context and Policies
- Transport Demand Management (TDM) is a profound new way of thinking about travel, one that attempts to influence travellers before they get into their cars (by promoting alternative modes and destinations of travel) and provides improved options for drivers who choose to use the road system (faster routes and more reliable travel times).
- TDM encourages sustainable travel and increases transport system efficiency. Trips are prioritised according to their value and cost to society as a whole (higher value trips and lower cost modes have priority over lower value, higher cost trips).
- TDM objectives include reduced traffic congestion, road and parking cost savings, increased safety, improved mobility for non-drivers, energy conservation and pollution emission reductions.
- Transport Demand Management is increasingly being referred to as "Mobility Management" as it increases travel options and encourages travellers to choose the most efficient mode for each trip. It does not eliminate automobile travel, since cars are the best mode for certain types of trips, but it tends to significantly reduce the amount of personal vehicle travel that would otherwise occur, particularly in urban areas. (Source: Todd Litman, 2003, "Mobility Management", Sustainable Transport: A Sourcebook for Policy-makers in Developing Cities (Module 2b), Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) GmbH, Eschborn, Germany).
- Managing travel demand is also about providing travellers, regardless of whether they drive not, with informed choices of travel route, time, and location - not just travel mode. Real-time information systems can now let travellers make better decisions about how they travel (mode), when they travel (time), which route they travel (route), and whether they travel at all.
- Transport Demand Management measures are by their nature innovative and often seen as being quite radical.
- They are criticised for placing unfair restrictions on automobile travel or as being harmful to consumers, regressive or wasteful. In reality, TDM measures improve travel options for everybody, including people who continue to drive.
- To be effective, they need to be thoughtfully planned and implemented. They therefore require strong political commitment, stakeholder involvement and advanced consultation.
TDM comprises an ever-expanding range of physical, operational, pricing and institutional measures:
- Congestion charging and road-tolling;
- Traditional mobility management programmes to encourage changes in travel behaviour;
- Public transport improvements;
- Measures to promote walking and non-motorised vehicle use;
- Telecommuting and the use of intelligent transport systems (its);
- Parking controls and pricing; and
- Physical traffic restraint measures.
- Managing Travel Demand: Applying European Perspectives to U.S. Practice, 2006, U.S. Department of Transportation, Federal Highway Administration (USA).
- Mitigating Traffic Congestion - The Role of Demand-Side Strategies, 2004, The Association for Commuter Transportation, Federal Highway Administration, Washington DC (USA).
Travel Demand Management: Some insights, Thomas GUÉRET, International Energy Agency.