Driver Braking Performance to Surprise and Expected Events

Meta-analyses have shown that the driver braking characteristics reported in the literature often vary due to differences in study methodologies (Green, 2000; Muttart, 2005; Summala, 2000). This paper provides additional insight on driver braking performance by 1) characterizing driver behavior during the execution of surprise and expected braking maneuvers, and 2) investigating the effect of gender, age, and vehicle driven on this behavior. Sixty-four drivers performed surprise and expected braking maneuvers from 45 mph (72.4 km/h) at an inflatable barricade, and subsequently performed expected braking maneuvers in response to an auditory alarm. Participants drove one of two instrumented vehicles: 1) a 2006 Mercedes-Benz R350, or 2) a 2007 Volvo S80. Drivers' braking inputs and corrected stopping distance were measured. Results indicate that drivers' braking performance varied by gender, age, and vehicle driven. These results and their relationship to the extant braking literature are discussed. The findings are expected to benefit those involved in crash reconstruction, researchers modeling driver braking behavior, as well as designers of brake-by-wire systems.