Transport demand management, often known as TDM, is the application of strategies and policies to reduce travel in single-occupancy private vehicles - or to redistribute it to places and times where it causes fewer negative externalities such as congestion or pollution. (See Demand Management)
Managing demand can be a cost-effective alternative to increasing capacity, and also has the potential to deliver better environmental outcomes, improved public health and more liveable and attractive cities. A major tool to implement TDM is the Travel Plan, which may be site-based, organisation-based or area-based.
Whilst many of the techniques of transportation demand management, and therefore of travel plans, involve non-technical approaches such as personal coaching and the design and production of printed material, ITS applications can play a major role in three areas:
Car-pooling, one form of this concept, also has urban planning benefits, in that building developers can be required (or choose) to provide fewer parking spaces, so saving land and costs.
A general source of expertise about TDM worldwide is the Victoria Transport Policy Institute (VTPI) in British Columbia, Canada (http://www.vtpi.org). There are also a number of national and regional organisations that are involved in the promotion and / or management of schemes designed to support TDM. These range from organisations promoting TDM itself, such as ACT TravelWise in the UK (http://www.acttravelwise.org), through to organisations promoting particular elements of travel demand such as Carplus in the UK. Carplus was established to support the development of car clubs and ride-sharing schemes in Britain. Its core stakeholders were operators, service providers and local authority partners.
Local authority membership of these organisations can help them achieve their targets in areas which TDM can address - such as congestion, air quality and social exclusion.
Another important group of organisations is the providers of software for matching journeys. These include companies producing scheduling applications - who may also provide applications specific to scheduling para-transit services. There are also companies who produce software for particular service markets which involve flexible operations – such as firms producing software for the taxi market and software providers for the delivery of travel plans.