Spacing and geometric design indexes of auxiliary lanes on two-lane highway in China

Guozhu Cheng,Lixin Wu,Lihui Qin,Sulu Zhang

doi:10.1177/1687814017723294

Abstract

Auxiliary lanes on two-lane highway are lanes setting on the right side of highway for the slow vehicles, and they can provide safe overtaking chances for cars using the original lane instead of the opposite lane. Based on the principle that the net benefit is greater than zero, the calculation model of the minimum spacing of auxiliary lanes on two-lane highway is established. After calibrating the model parameters, recommended minimum spacing values for auxiliary lanes are given corresponding to different highway classes, design speeds, and terrains. Based on traffic simulation data, the relationship model is established among the length of auxiliary lane section with uniform widths, traffic volumes, and driving speeds. By analyzing the design capacity of two-lane highway, suggestion values of the length of auxiliary lane section with uniform widths are given for two-lane highway with different design speeds and terrains. Based on driving safety and questionnaire survey on lateral vehicle spaces, calculation formula and suggestion values are presented for the width of auxiliary lanes on two-lane highway.

Highlights

The cost of auxiliary lanes increases with the decrease of spacing, so calculation model of minimum spacing for auxiliary lanes can be given according to the principle that the net benefit must be greater than zero
In equation (17), driving speed is taken as design speed, and traffic volume is taken as design capacity of two-lane highway in ‘‘Technical Standard of Highway Engineering (JTGB01-2014).’’3 According to Table 7, the length of auxiliary lane section with uniform width can be calculated
Based on the traffic simulation and questionnaire survey, this article conducts the research of the length and width of auxiliary lanes on two-lane highway

Summary

Introduction

According to the statistics by the end of 2015, the total mileage of highway is more than 4.58 million kilometers in China, and the two-lane highway accounted for less than 30% of the total mileage.[1]. According to the related researches of traffic accidents forecasting,[19] the safety benefit calculation model of setting auxiliary lanes on two-lane highway per year was given as equation (1). The sum of all discount values is the safety benefit of setting auxiliary lanes on two-lane highway The sum of all discount values is traffic operation benefit of setting auxiliary lanes on two-lane highway The cost of auxiliary lanes increases with the decrease of spacing, so calculation model of minimum spacing for auxiliary lanes can be given according to the principle that the net benefit must be greater than zero It can be obtained by above analysis and shown as equation (15). In accordance with the study of the relevant literature,[24] the calculation models of operating speed on two-lane highway are shown as equation (16)

21.42 Class II

Findings

Conclusion