It is now widely accepted that providing additional road capacity can induce extra traffic. Therefore, it is important to consider what occurs when road capacity is reduced; is there a corresponding degeneration of traffic? The recent closure of Hammersmith Bridge, London to private cars and vans provided an ideal opportunity to study possible degeneration effects. Drivers who previously used the bridge were invited to participate in a survey via a postcard given to them two days before the bridge was closed, and soon afterwards interviewed by telephone to find out how their travel habits had altered as a result of the closure; some of them were interviewed again eight months later. This paper reports the market research findings, including respondents' changes in modal split and attitudes on various questions, and outlines tentative results about the closure's effect on bus operations. For most respondents, the bridge's closure had not contributed to them no longer making work journeys, but a considerable number of respondents changed the location of their shopping to more accessible places. At the time of the closure, some improvements were made to the three bus services using the bridge, and the numbers of passengers travelling over the bridge rose substantially. There was a slight increase in local Underground travel.
Samenvatting