Variability of Green Time to Discharge a Specified Number of Queued Vehicles at a Signalized Intersection

Yi Zhao,Qian Wan,Yankai Zong,Yongfeng Ma,Jian Lu

doi:10.1155/2017/3723575

Abstract

The aim of this paper is to study the headway distribution of queued vehicles (less than 16 vehicles) at signalized intersections. Existing studies usually take the average statistics of headway at any queuing place. When different percentile points of statistical data are assigned to headway, the passing rate (the rate of all queued vehicles passing the stop line) under the ideal signal timing scheme varies. When selecting the mean value, the passing rate of a queue of fewer than 16 vehicles is no more than 65%. When selecting 75% as the percentile, the passing rate is up to 94%. The queue length also decides the assigned percentile of headway to ensure the passing rate reaches a certain level. The value assignation of headway directly affects lane capacity and start-up loss time. This paper provides a new perspective on parameter calibration and will make the signal timing algorithm method more effective.

Highlights

The signal control method is one of the most universal and effective intersection control methods
The aim of this paper is to study the headway distribution of queued vehicles at signalized intersections
As described by Crabtree [2], TRANSYT tries to optimize static signal timing through traffic simulation, but the discharge rule of queued vehicles affects the results of simulation

Summary

Introduction

The signal control method is one of the most universal and effective intersection control methods. Through analyzing the survey data of signalized intersections of a Virginia highway, Denney Jr. et al [10] discovered that headway decreases toward the back of the queuing line, but this feature is not obvious in the central and interior through lanes He et al [11] found that when the light turns green, the headway is influenced by the queuing position: the lead vehicles have a larger headway of up to 3.85 seconds, while the reaction time lapses in the trailing vehicles, and this rule no longer applies. By summarizing the existing research results, it has been found that most studies on headway distribution are based on measured data, and measured data usually uses average values as the headway of vehicles at different queuing positions It is a reasonable method when using statistics. The final section presents the conclusion and recommendations for future study

Data Sources

Headway Distribution Characteristics Analysis

Headway Selection Analysis

Implementation Discussion

Findings

Summary and Discussion