Road layout design standards and driver behaviour

This paper describes experimental studies, undertaken for the Highways Agen cy, in which the role of driver characteristics in three specific component s of the driving task - speed choice, emergency braking and overtaking - ha ve been explored. The purpose of the work was to provide the design enginee r with a more detailed insight into the characteristics of drivers using th e roads and their performance in critical situations. A simple stratificati on of car drivers has been derived from speeds measured at a sample of trun k road sites in Great Britain in combination with the personal characterist ics 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.