Abstract
When the lead car decelerates and the host car closes its distance to it, the host car’s driver must use their depth perception to decide whether and when to decelerate his/her car. Time-To-Collision (TTC) is often used as a control parameter in Driver Assistance Systems when designing them to fit the drivers' feelings and behaviors. This study investigated the temporal relationship between the visual angle (as a visual trigger) of the host car driver’s perception of the width of the lead car when closing the distance between them and the onset of braking. It was concluded that the inverse of the TTC (iTTC) was a well-represented parameter of the driver’s perception and basically represented the parameter on the onset of braking.
Keywords: TTC, Brake Trigger, Car-Following, Risk Perception