Geometric delay at non-signalised intersections

Abstract

Delay to vehicles at intersections is an important factor in the choice of intersection type and frequently attention is focussed on queueing delay which occurs at peak flow times. There is however a further source of delay which is found regardless of traffic conflicts, caused by vehicles slowing down and subsequently accelerating as they negotiate the junction. As this form of delay is determined by the size and shape of the junction, it is referred to as ‘geometric delay’. Because geometric delay takes place throughout the whole of the day it often is a substantial portion of the whole of the delay.