Abstract
The purpose of the study is to investigate the minimal acceptable distance between two adjacent vehicles using a driving simulator. One factor within subject design was adopted for the experiment. As independent variable, the relative velocity between two adjacent vehicles was selected. The relative velocity had 5 levels: 0, 20, 40, 60, 80km/h. For the statistical analyses, the minimal acceptable distance between two adjacent vehicles and time-to-collision (TTC) were selected as dependent variables. The TTC means the value that the minimal acceptable distance divided by the relative velocity at the time that the driver started to press the brake pedal. Thirteen drivers participated in the experiment. The subjects were asked to drive at 100km/h and to press the brake pedal at the moment when he felt that the vehicle could collide with a preceding vehicle. The velocity of the preceding vehicle was randomly selected among 0, 20, 40, 60, 80km/h. The each treatment was repeated 3 times. The subjects drove a simulated track course for 15 minutes. The results showed that 1) the minimal value of the TTC at the moment when the subjects pressed the brake pedal was about 2 seconds, regardless of the relative velocities of two adjacent vehicles 2) as the relative velocity of two adjacent vehicles increased, the average value of the TTC decreased. The differences among driver’s braking behavior patterns were discussed.
Keywords: Minimal acceptable distance, active safety, ergonomics, driver’s behavior pattern