A Study on the Functional, Environmental and Visual Characteristics of Road Section and Its Relation to Traffic Safety

1.项目目标项目的目标是：(1)开发一些新的评价路段功能特征的指标，(2)将这些指标与每个路段的交通事故风险联系起来，(3)找出驾驶员视力的一些基本行为及其对道路环境的依赖。本项目的主要研究成果如下：(1)应用林氏的量化理论Lt；III和Gt；，开发了两种新的测量方法，该方法基于每个路段的14个变量。一种是路段通行能力的度量，另一种是可能交通量的度量。这两个指标用于评价路段的功能特征，进而将路段划分为功能级别。(2)尝试将这两个指标与每个路段的交通事故率进行关联，发现行驶能力与交通事故率有较好的关系。(3)通过对目标仪测量的数据进行分析，发现驾驶员视力的一些基本行为。一是驾驶员在道路环境中的视线停留时间服从k=2的Erlang分布；二是驾驶员的视线随道路环境的复杂程度而频繁变化。因此，道路环境的设计应该尽可能简单，不干扰驾驶员的视力，不带信息的误解。

1. Objectives of ProjectThe objectives of project are; (1) to develop some new measures for evaluating the functional characteristics of road section, (2) to relate these measures with the risk of traffic accident of each road section, (3) to find some fundamental behavior of driver's eye-sight and its dependence with road environment.2. Findings of ProjectThe main findings of project are as followings:(1) Two new measures which are based on 14 variables of each road section were developed by use of Hayashi's quantification theory type <III> . One is the measure of travelling ability of road section and the other is the measure of possible traffic volume. These two measures are used to evaluate the functional characteristics of road section and then to classify the road sections to its functional level.(2) An attempt was made to relate these two measures with traffic accident rate of each road section and found out that travelling ability had a better relationship with traffic accident rate.(3) Some fundamental behavior of driver's eye-sight were found by analyzing data which were measured by use of eye-mark recorder. One of these is that the time of eye-sight stop in the road environment is distributed according to Erlang distribution with k=2. Other is that the driver's eye-sight is frequently changed according to the degree of complexity of road environment. Therefore, the design of road environment should be as possible as simple not disturbing the driver's eye-sight and not taking the misunderstanding of information.