Road layout design standards and driver behaviour

This paper describes experimental studies, undertaken for the Highways Agency, in which the role of driver characteristics in three specific components of the driving task - speed choice, emergency braking and overtaking - have been explored. The purpose of the work was to provide the design engineer with a more detailed insight into the characteristics of drivers using the roads and their performance in critical situations. A simple stratification of car drivers has been derived from speeds measured at a sample of trunk road sites in Great Britain in combination with the personal characteristics of the drivers obtained by postal questionnaire. The emergency stopping study explored the determinants of emergency stopping performance using a simple simulator, and overtaking behaviour on single carriageway roads was studied both in a simulator and on the road.