Drivers' estimates of time to collision were determined in a laboratory simulation using film segments made from a following vehicleapproaching a lead vehicle, which was also in motion. Headway, approach speed, and viewing time were varied to make a total of 48 conditions. It was found that, provided the angular velocity subtended bythe lead vehicle was above a threshold value of about .003 radians/sec, the driver was able to give reasonable estimates of time to collision. The standard deviation of the estimates varied linearly withthe time to collision. Although drivers underestimated the time to collision when it was small, the large standard deviation shows the possibility of rear-end collisions due to poor estimation of time tocollision, especially when the times for control action and vehicledeceleration are considered. (A)
Samenvatting