Rick F Guyon - Stopping Distance - Richard F Guyon

Rick F Guyon - Stopping distance includes the distance traveled before the brakes are applied as well as the distance during the breaking manuever. The breaking perception reaction time is also referred to as the PIEV time, using an acronym for perception, identification, emotion, and volition. PIEV time varies widely from person to person. Though the median value is approximately 0.90 sec for unexpected events, individuals with slow reaction times may require up to 2.7 seconds. 2.5 seconds is the value used by AASHTO for determining the minimum stopping sight distances, the value that is appropriate for approximately 90% for the population.