An Exploratory Hazard-based Analysis of the First Discharge Headway

The discharge headway is an important parameter in determining intersection capacity. However, it is difficult to quantify the discharge headway of individual queuing vehicle because of the great difference in the vehicle characteristics and traffic conditions. The current research aims at analyzing the first discharge headway at signalized intersections in Beijing. It introduces a hazard-based model to analyze the first discharge headway of queuing vehicles, and proposes the parameter estimation method. The model has been calibrated and validated on the basis of data collected from Beijing. It has been found that the first discharge headway, which is much longer than that in other cities, is very much dependent on the vehicle type and complexity of the intersection. It also indicates that disturbances during the starting and moving of the first vehicle increase the first discharge headway drastically. Without regard to other independent factors of traffic conditions, the starting disturbance is expected to increase the average value of the first discharge headway from to 3.99 s to 5.47 s, while the moving disturbance prolongs it from 4.15 s to 6.65 s. © 2011 Published by Elsevier Ltd.