The rate of provision of bus-based park and ride facilities on the fringes of UK urban areas has grown in recent years. However, there has been a debate about whether the schemes reduce traffic. Research published in 1998 for the UK Government considered eight case studies and was interpreted by some as providing reassurance that park and ride can have traffic-reduction benefits. The present paper offers a new approach to the appraisal of the same eight park and ride schemes, separating the analysis into urban and extra-urban components. The urban-area analysis considers the net result of intercepting cars on the edge of urban areas and running additional dedicated bus services from the car parks. The finding is that traffic was avoided in seven out of eight cases. The analysis of the extra-urban effects of park and ride considers three sources of traffic increase: motorists that are intercepted detouring to reach sites, users switching from public transport services and motorists making additional trips. All are found to be important phenomena, with the total additional traffic generated outside the urban area being greater than that avoided within the urban area in every case study. It is concluded that the main effect of the schemes is traffic redistribution, and that their role within traffic restraint policies is unlikely to be directly one of traffic reduction. (C) 2000 Elsevier Science Ltd. All rights reserved.