Abstract: Vehicle conversion coefficient is a basic parameter on calculating traffic volume. In order to calculate traffic volume accurately, it is necessary to convert a bicycle into a standard car. The former studied think that the conversion coeficient is 0.2 when a bicycle is converted into a car. But the paper does the research of bicycle conconversion coeficient on urban road section and finds that the conversion coefficient 0.2 is not exact enough on urban road section. There are two forms on city road section, one is that road is not separated; another is separated, so the conversion coefficient should be calculated respectively according to the two forms. The paper puts forward the concept of effective lane-width and established a model of conversion coeficient. And then, taking advantage of survey data in Shijiazhuang city, the paper gives several examples about calculating bicycle conversion coeficient on road which cars and bicycles are separated and on mixed traffic road respectively.

Key words: conversion factor, effective lane-width, mixed traffic, bicycle

摘要： 车辆换算系数是统计交通流量的基本参数，为了准确计算道路的交通流量，有必要将自行车换算成标准小汽车。以往研究认为自行车相对于标准小汽车的换算系数为0.2，本文对城市道路路段自行车换算系数进行了研究，发现这个数值用在城市道路路段上已经不够准确。城市道路路段分为有机非物理隔离设施和无机非物理隔离设施两种形式，换算系数也应该根据这两种情况分别计算。本文提出了车道有效宽度的概念，建立了自行车相对于机动车的换算系数模型，并结合模型，利用石家庄交通调查实测数据，分别得到城市道路路段有、无机非物理隔离设施两种情况下的自行车换算系数。

关键词: 换算系数, 车道有效宽度, 混合交通, 自行车