Quantifying Driver Response Times Based upon Research and Real Life Data

The purpose of this paper was to build upon previous research, identify the variables that significantly influence driver response times, and to determine the amplitude (constant) of that influence. The goal is that this research will explain why seemingly analogous published studies have come to very different driver response time results. An analogous driver response situation is defined as being in one of four groups: (1) lead vehicles that were stopped or moving slowly, (2) being cut off (when a vehicle changes lanes into the path of the responding driver), (3) path intrusions, or (4) known lights, icons or sounds. It was found that research that measured response times in analogous situations can be used to estimate the mean response time for a particular situation if adjustments are made to account for methodological differences between the studies. Non-analogous studies are poor predictors of driver response. (An anticipated light stimulus response cannot accurately predict the response time to a path intrusion or lead vehicle). Mean driver response times can be predicted within 400 ms without accounting for individual difference. Therefore, external validity can be obtained regardless of the testing method (closed course, simulator or road), as long as the subject is unaware of either the stimulus or the appropriate response. Having a subject respond to multiple events does not (by itself) suggest that drivers will respond significantly faster.