动态视角下的城市道路交通网络失效评价模型

利用可靠性相关理论,在对交通网络状态变化规律分析的基础上,给出了了城市道路交通单元及交通网络的‘失效—非失效’态的表达方法;分析了路段单元及交通网络的状态从观察起始点t0到首次演变到‘失效态’的时间分布规律,并以此为基础推导了城市道路单元及交通网络的失效概率、平均失效时长、失效率以及条件失效时长等失效评价模型,给出了模型标定的方法。以国内某城市核心城区5条道路单元组成的路网为实例,对首次失效时间进行了分布拟合及检验,对模型进行了标定,并将模型计算结果与实际观察结果进行了对比。结果表明,利用对数正态分布来拟合首次失效时间较为理想,而且模型的计算结果与实际观察结果也非常接近,表明模型具有良好的实用性。

Urban traffic network failure model under dynamic perspective

Based on the reliability theory, the expression of the ''failure---non failure'' state of the urban road traffic unit and the traffic network is given after the change law of their states is analyzed; the time distribution of the link unit and the traffic network is analyzed from the observed starting point t0 to the "first failure state". Based on these, the failure probability, average failure time, failure rate and conditional length of failure time of the urban road unit and traffic network are deduced, the method of model calibration is also given in this paper. A road traffic network that composed of five road units in a core city of China is taken by an example, the first failure time of the road units and the traffic network are fitted and checked, the model calculation results are also compared with the actual observation results. The results show that it is better to use logarithmic normal distribution to fit the first failure time, and the calculation results of the model are very close to the actual observation results, which shows that the model has good practicability.