山区双车道公路延误车头时距分析

Analysis of Delay Headway on Two-lane Highways on Mountainous Areas

跟车时间百分比(延误率)是衡量双车道公路服务水平的一个重要指标.我国将一般双车道公路上小于等于6s的车头时距定义为延误,并作为划分道路服务水平的因素之一.在山区双车道公路进行了阻车实验,并对获得的车头时距、车速等数据进行分析,认为山区双车道公路延误车头时距与前后车速度差的关系不同于一般双车道公路,建议不采用跟车时间百分比作为山区双车道公路服务水平的划分指标,从而为我国山区双车道公路通行能力的研究提供数据依据.

Percent Time-Spent-Following （Percent Time Delay） is an important index to estimate Level-of-Service of tow-lane highways. Vehicles traveling at headways of less than 6 seconds may be taken to be followers on two-lane highways in China. Through the analysis using data of headway, speed, and other characteristics from interrupting traffic flow on a highway on mountainous areas, the relationship between delay headway and speed dispersion differs from that of on level areas. The paper advises not to adopt the Percent Time-Spend-Following as the index of measuring the LOS. And the result can provides some useful data to the study of highway capacity about tow-line highways on mountainous areas.