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选取基本段、合流段和分流段作为比较对象,对快速路不同路段类别的事故率与交通流状况的关系进行研究。采用临界速度区分饱和流和非饱和流,利用交通密度划分交通流水平,统计其事故率,并比较直、曲线形和分(合)流模式以及分(合)流点上(下)游区事故率分布差异。研究结果表明:对于非饱和流,事故率随交通密度呈现二次函数变化,其中合流段事故率显著大于分流段和基本段事故率;对于饱和流,事故率随交通密度呈现指数函数变化,但3种路段类别间事故率差异不显著,直、曲线形和分(合)流模式以及分(合)流点上(下)游区对事故率变化趋势有较大影响,其中在分流段的影响更为显著。
The basic section, the confluence section and the diversion section are selected as comparative objects to study the relationship between the accident rate and traffic flow in different sections of expressway. The critical speed is used to distinguish between saturated and unsaturated flow, traffic density is used to divide the traffic flow level, and the accident rate is calculated. The straight, curvilinear and sub-flow patterns as well as the upper (lower) tour area Accident rate distribution differences. The results show that accident rate changes quadratically with traffic density, and the accident rate of confluence is significantly larger than that of distributary and basic section. For saturated flow, the accident rate changes exponentially with the traffic density, There was no significant difference in the accident rates among the three road sections. The direct, curvilinear and sub-combined flow patterns as well as the upper and lower (downstream) flow points had a significant effect on the change of accident rates. Among them, The impact is more significant.