The problem of the amber signal light.

This paper is a composite of 2 studies which have appeared relatively recently and is concerned with the problem of the amber phase of traffic signals. In particular each of these studies is an approach to the understanding of the problem that arises when a motorist is confronted with the onset of the amber phase at a moment when the driver is too close to the intersection to stop safety or comfortably and yet, because of the duration of the amber phase, he is too far from the intersection to pass through before the red phase begins.