Delay Estimation at Signalized Intersections with Variable Queue Discharge Rate

Abstract

The techniques developed for delay estimation in most traffic signal design guidelines are based on the assumption that queue discharge rate at signalized intersections becomes stable after a few vehicles pass through the stop line, which is termed as saturation flow rate. This assumption has been challenged in recent times as a number of field observations in different parts of the world reported an increasing queue discharge rate observed along the back of the queue. This paper proposes an empirical model that is capable of capturing the queue discharge behavior observed at signalized intersections. The model is implemented to estimate delay and compared with the existing delay models. The results revealed that the proposed model can overcome the deficiencies of the existing models and can estimate delay more accurately.