Overtaking Safety Evaluation and Setting of Auxiliary Lane on Two-Lane Highway in China

Guozhu Cheng,Liang Xu,Lixin Wu,Yuxia Wang,Lihui Qin

doi:10.1155/2016/2603828

Abstract

Overtaking experiments on four two-lane highways were conducted. The data of overtaking conflict time (the time difference between the time of driving back to the original lane and the time of meeting with the first opposing vehicle) and experimental drivers’ risk feeling were observed. Membership was adopted to denote the experimental drivers’ risk feelings which also denote the severity of traffic conflict. Membership ranges from 0 to 1 and corresponding risk becomes higher; that is, traffic conflict becomes more serious. According to the observed relationship between overtaking conflict time, and drivers’ risk feeling membership, Cauchy distribution function was adopted as membership function. The thresholds of the severity of traffic conflict were determined through Delphi method. The relationship model among traffic volume, overtaking conflict time and design speed was established according to experimental data. Then the idea of setting auxiliary lane on two-lane highway in China was presented. And the traffic volume values that need setting auxiliary lane corresponding to different design speed and traffic conflict degree were given according to the established model. It is expected to improve the traffic safety level of two-lane highway in China through setting auxiliary lane.

Highlights

By the end of 2013, the total mileage of Chinese classified highway has reached 3.7556 million km and the ratios of the second-class highway, the third-class highway, and the fourth-class highway are 82 percent
In order to describe the severity of traffic conflict accurately, Delphi method and assignment method based on the fuzzy theory were adopted to analyze the traffic conflict qualitatively, and the membership function of overtaking conflict time was given
It is suggested that auxiliary lane should be set when traffic volume of opposing lane exceeds the boundary value between minor and general conflicts because serious conflict is very dangerous

Summary

Introduction

By the end of 2013, the total mileage of Chinese classified highway has reached 3.7556 million km and the ratios of the second-class highway, the third-class highway, and the fourth-class highway are 82 percent. Developed models that explain the minimum time to collision and passing gap acceptance by simulator and analyzed age and gender differences in overtaking maneuvers on two-lane rural highways [2,3,4]. Schneider et al used the negative binomial model to evaluate the effects of geometric characteristics on rural two-lane highway safety [5]. Wu et al developed mixed logit models to analyze driver injury severities in single-vehicle and multivehicle crashes on rural two-lane highways in New Mexico [7]. Zeng and Schrock analyzed safety effectiveness of composite shoulders on rural two-lane highways [14].

Experiment

Results and Discussion

Conclusions