Factors Related to Drivers’ Braking Operation in Response to a Crossing Vehicle Approaching from the Side Direction

We conducted driving simulator experiments with 15 participants to identify factors related to drivers’ judgment of when and how to brake. We set up a situation in which a subject vehicle encountered a target vehicle at an open non-signalized intersection to simulate a crossing collision. Drivers in the subject vehicle were instructed to apply the brakes when they felt danger. Factors investigated were azimuth angle to the target vehicle, position of target vehicle when the subject vehicle arrives at an intersection, visual angle of target vehicle, and relative distance between subject vehicle and target vehicle. We analyzed both their time differentials and increase rates. Statistical analysis indicated that the factors most closely related to the drivers’ braking judgment are relative distance between subject vehicle and target vehicle, and azimuth angle to the target vehicle.