Analysis of a Signalized Intersection with Dynamic Use of the Left-Turn Lane for Opposite through Traffic

Yongtao Zheng,Wei Wang,Dongya Li,Xuedong Hua,Jialiang Xiao

doi:10.3390/su12187530

Abstract

For signalized intersections with a quantitative imbalance between the approach and exit lanes, this study proposes a method for the dynamic use of the left-turn lane for opposite through traffic to improve the efficiency of the signalized intersection. The complete scheme of this method mainly consists of three parts: the location routes of the dynamic lane, the temporal scheme, and the spatial scheme. To demonstrate the effectiveness of this method, a simulation scheme comparing the intersection with and without the dynamic lane is designed using VISSIM. The parameters of the simulation model, including the traffic simulation environment parameters and built-in VISSIM models, are calibrated by the field data collected from an intersection in Nanjing, P. R. China. The results of the simulation indicate that this method decreases the average delay and average queue length of the intersection effectively for the intersection with a quantitative imbalance between the approach and exit lanes under the conditions of different through volumes or left-turn ratios. The maxima were 46.9% (average delay) and 68.3% (average queue length) for all situations. Lastly, some suggestions are presented for the application of this method.

Highlights

Signalized intersection approaches are usually channelized to serve directional flow and facilitate signal control [1]
The present study addresses the following research questions: (1) What conditions should be satisfied should be satisfied to apply this method? (2) How can we determine the length of the dynamic lane to apply this method? (2) How can we determine the length of the dynamic lane while considering safety? (3) How much is the efficiency of the intersection improved by using this method? The results of this study potentially provide a new perspective for engineers and designers to solve the difficulties of special intersections
It is not valuable to explore the regularity of delay changing with independent variables because the target is to evaluate the performance of the dynamic lane compared to the field

Summary

Introduction

Signalized intersection approaches are usually channelized to serve directional flow and facilitate signal control [1]. More than one approach lane is used to serve one single directional flow due to large traffic demands in some cases, and the exact number of such lanes is easy to calculate according to the volume. A special kind of intersection still exists in the downtown areas of cities in developing countries like China, whose number of exit lanes is less than that of the approach lanes. This special kind of intersection features a quantitative imbalance between the approach and exit lanes—i.e., an imbalanced intersection. Due to the decrease in lanes, a merging conflict originating from the through flow is generated in the intersection area alongside the existing conflicts. Drivers have to decrease their speed to avoid

Methods

Results

Conclusion