Abstract
This paper deals with the braking timing of elderly drivers. We conducted the outdoor experiments on a test course in order to examine which factor would mostly affect the driver's judgment of braking timing using 6 elderly participants. Participants in the trailing vehicle applied brakes according to his/her subjective judgments to prevent rear-end collision. We revealed that the rate of change of visual angle. which is the inverse of TTC, is mostly related to the driver's judgment of braking timing by discriminant analysis.
