This study investigates techniques for studying the incidence of unsafe driving actions (UDAs) in both the accident and normal driving population in an attempt to develop an overall plan for measuring relative crash risk of UDAs. Stage 1 re-analysed the Adelaide in depth study (Mclean et al. 1979) coding driver behaviour with definitions from previous studies. During this procedure it became apparent that an improved system for assigning UDAs was required. This led to the development of a flow chart technique which was found to be both reliable and sufficently detailed. Stage 2 applied the flow chart technique to police crash report forms. A pilot study suggests that additional information held at Police Headquarters may be the most successful way to re-attempt Stage 2. Stage 3 piloted several techniques for observing UDAs in the normal driving population. Road safety. Driving. Safety. Road accidents. Techniques Accident reports. Driver behaviour
