Steer or Brake?: Modeling Drivers’ Collision-Avoidance Behavior by Using Perceptual Cues

Abstract

Driver models have been developed to capture collision-avoidance behaviors, yet there is a lack of understanding of what perceptual processes influence drivers’ choices to brake or steer. A statistical model of these decisions was developed with cluster analysis and multinomial logistic regression with data from a simulator study of drivers’ responses to rear-end collisions. Drivers’ choices of responses were clustered on the basis of the maximum values of the magnitude of braking and steering forces, starting from the time at which the driver looked back to the road, just before initiating the avoidance maneuver, to the end of the maneuver. The clusters identified three types of responses: medium to high braking with medium to high steering, medium to high braking with mild steering, and mild braking with medium to high steering. The perceptual variables such as the optical angle, the expansion rate of the optical angle, and their ratio were used to predict the drivers’ choice of response. The results show that, of the perceptual variables, the combination of optical angle and tau performs as well as or better than others in predicting the choice of response. The mode and timing of an alert from a collision-warning system did not influence the drivers’ choices. These results can inform driver behavior models to guide design and assess benefits of advanced driver assistance systems.