The assumption of a reaction time value for drivers responding to road situations is fundamental for the design requirements involving sight distance, and in the modelling of stopping distances. This response time is frequently referred to as the perception-reaction time in traffic engineering literature. The procedures used in previous studies have generally been deficient on one of several grounds. The majority of studies have used briefed subjects in an experimental situation. The duration of various processing stages have generally been arrived at by a subtractive technique. Responses have usually been assumed to be the result of speeded processes. Within single studies, the stimulus situations examined have typically been limited.The requirement for unobtrusive observational techniques is stressed so that reaction time estimates can be obtained that are representative of real world performance. This approach was used in the study reported here to obtain data for a range of eliciting stimuli. Vehicle speed was observed for some situations to allow an assessment to be made of whether driver response times depend on vehicle speed. The data showed generally that faster drivers had lower reaction times under otherwise similar conditions (A). For the covering abstract of the conference see E217780.
Abstract