The linkage between Hazard Perception Ability and the Proportion of Hard Braking Events

Drivers with higher proportion of hard braking events have greater potential to be involved in an accident. We investigated if the proportion of hard braking events can be accounted for by hazard perception test (HPT) scores. According to hazard perception theory, drivers with better hazard perception ability can identify developing hazards earlier and therefore, avoid the need to brake hard. Based on this theory, we hypothesized that the link between HPT score and the proportion of hard braking events would be stronger if the threshold that defines hard braking is higher. Thirty-three drivers completed an HPT and used a smartphone app that recorded their vehicle kinematics. We chose a range of thresholds for hard braking, and for each threshold, we tested the coefficient of HPT score in a binomial regression model on the proportion of hard braking events. In accordance with our hypothesis, we found that the coefficients changed as a function of the threshold for hard braking. This finding was based on a significant negative spearman correlation between the coefficients and the threshold and on linear functions that we derived from a model that allowed the coefficient of HPT to vary according to the threshold. Our findings show that hard braking events are related to hazard perception ability and can inform safety interventions that include monitoring of braking events. From a theoretical perspective, our findings provide strong support to hazard perception theory.