22: Effectiveness of Transport Policies in Reducing Car Travel

Policies intended to solve problems caused by excessive traffic usually seek to change travel behaviour. These changes are assessed with extensive empirical evidence, including inference from the extent of behavioural change that occurs for other reasons such as age and income, case studies of increasing or reducing road capacity, econometric analysis of the effects of fuel price and public transport fares, and observation of impacts of soft measures such as travel plans and improved information. The results show a dynamic process of adjustment over periods of some years, with impacts that are larger, but more complex, than often assumed.

This chapter addresses the empirical issue of what actually happens in practice when policies aimed at reducing car use are implemented. Is it, in fact, possible to change travel behaviour? The underlying proposition in the chapter is that by understanding how travel behaviour does change, we are better equipped to understand how it can be changed.