Linking road traffic accidents with skid resistance: recent UK developments

When, in 1988, the UK Department of Transport first introduced requirements for skid resistance on its trunk road network, it introduced the concept of �investigatory levels� to be compared with measurements from routine skid resistance surveys. At the heart of this process was a link between the risks of wet skidding accidents occurring and the levels of measured skid resistance on the road. Initially, this was based upon a survey of a sample of the network at which the time was limited by survey capacity and computing power. The skidding standards have recently been revised and as part of this process, a new assessment of the link between accident risk and skid resistance has been made. This has involved a study of the whole Trunk Road network. This paper will review the historic background and then describe in more detail the recent study and its findings, how the results compare with the historic work and the changes that were shown to be appropriate for application in the revised standard introduced in August 2004. (a) For the covering entry of this conference, please see ITRD abstract no. E212865.