行车间距分析

本试图通过分析行车间距与车速的关系，以新的理念和方法确定道路通行能力．首先综合分析了行车间距的特征，内容包括安全间距和期望间距等．前取决于对安全程度的要求，后则取决于驾驶员的行为特征，也可以说是交通流的模式．安全间距和期望间距都是速度的函数，根据它们的曲线形状，可以找到二的交叉点，这个交叉点就是道路通行能力值所在，它代表了满足最小安全度要求的最大流率．

Analysis of distance headway

By means of the relationship between speed and distance headway, this paper attempts to directly determine the road capacity based on a new concept. At first it makes a comprehensive analysis of distance headway, including safe distance headway and desired one. The former is decided by the demand for the degree of safety, and the latter depends on the motorists' behavior, i.e. the model of traffic flow. Both of them are functions of speed. According to the characteristics of their curves, we can find a crossing point that is the capacity of a road segment. This capacity represents the maximum flow rate meeting the minimum safety requirement.