A Probability Model of Bicycles Crossing Vehicle-bicycle Separation Lines

Vehicle-bicycle separation lines are frequently used to isolate motor vehicles from bicycles on China's urban roads. Conflict between motor vehicles and bicycles exists in these road sections. It is regularly caused by bicycles crossing the vehicle-bicycle separation line onto the motor vehicle lane. Thus, it is imperative to research the probability of crossing travel of bicycles. First, two presumptions for bicycles to cross travel are stated. One is that bicycles need to cross the traffic marking; the other is that the space among the adjacent motor vehicle flows is available for bicycles to cross. With this observation, the probability of conflicts between motor vehicles and bicycles can be obtained as a product of their probabilities. Based on this probability, the result was summarized as follows: the probability for bicycles crossing the traffic marking obeys a negative exponential distribution, which is derived. The result was shown by theoretical analysis and was compared to actual survey data. The available probability for bicycles entering into motor vehicle flow was found by the use of a traffic survey. Therefore, a probability function was proposed with different spaces that led to a probability model for vehicle-bicycle conflicts. At last, using the survey data, the probability model proved to be correct.

摘要城市道路上的机动车道和非机动车道经常利用交通标线来进行隔离. 在这些路段中, 机动车与非机动车之间的冲突经常是由于非机动车越过交通标线进入机动车道而引起的.非机动车越过交通标线往往需要两个前提, 一是非机动车有越线的需求, 二是相邻的机动车道上有可以满足非机动车越线行驶的车头间距, 即所谓的开区间.因此, 机非标线隔离路段机非冲突的概率可以认为是以上两类事件的概率之积.本文研究结果显示, 非机动车越线行驶的需求遵从负指数分布的概率模型, 这与理论分析结果和实际调查数据均相符. 同时, 结合实际的交通调查, 得到了机动车流中开区间出现的概率函数.由此最终得到了非机动车越线行驶的概率模型.