Factors with the Greatest Influence on Drivers´ Judgment of When to Apply Brakes

This paper examines the factors that most strongly affect drivers´ judgment with regard to braking timing. Experiments were conducted with 7 participants on a test course. Participants in the trailing vehicle applied brakes according to their subjective judgments on how best to prevent a rear-end collision. Various factors such as following car speed, distance between two vehicles, relative velocity, time-to-collision (TTC), rate of change of visual angle (which is the inverse of TTC) and others were examined in discriminant analysis. It was revealed that the rate of change of visual angle, which is the inverse of TTC, is the most closely related to a driver´s judgment of when to apply the brakes