Ma Xiaoliang, Andréasson Ingmar
Center for Traffic Simulation Research (CTR), Royal Institute of Technology (KTH), Department of Transportation and Logistics, Stockholm, Sweden.
Accid Anal Prev. 2005 Nov;37(6):1162-9. doi: 10.1016/j.aap.2005.06.017. Epub 2005 Aug 2.
Intelligent speed adaption (ISA) is one type of vehicle-based intelligent transportation systems (ITS), which warns and regulates driving speed according to the speed limits of the roads. Early field studies showed that ISA could reduce general mean speed levels and their variances in different road environments. This paper studies the effects of various ISA penetration grades on pedestrian safety in a single lane road. A microscopic traffic simulation tool, TPMA, was further developed and used to implement different ISA penetration grades. Momentary spot speed and traffic flow data are first logged in the traffic simulation for later prediction of pedestrian safety. Then a hypothetical vehicle-pedestrian collision model is extended from early researches in order to estimate two safety indicators: probability of collision, and risk of death. Finally, Monte Carlo method is applied iteratively to compute those safety indices. The computational result shows that raising ISA penetration in traffic flow will reduce both the probability of mid-block collision between vehicle and pedestrian and the risk of death in the collision accidents. Furthermore, the decrease of the risk of death will be more prominent than that of the collision probability according to this method.
智能速度适应（ISA）是基于车辆的智能交通系统（ITS）的一种类型，它根据道路限速来警告和调节行驶速度。早期的实地研究表明，ISA可以降低不同道路环境下的总体平均速度水平及其方差。本文研究了不同ISA渗透率等级对单车道道路行人安全的影响。进一步开发了一种微观交通模拟工具TPMA，并用于实现不同的ISA渗透率等级。首先在交通模拟中记录瞬时点速度和交通流数据，以便稍后预测行人安全。然后，从早期研究中扩展了一个假设的车辆 - 行人碰撞模型，以估计两个安全指标：碰撞概率和死亡风险。最后，迭代应用蒙特卡罗方法来计算这些安全指数。计算结果表明，提高交通流中的ISA渗透率将降低车辆与行人在路段中间碰撞的概率以及碰撞事故中的死亡风险。此外，根据该方法，死亡风险的降低将比碰撞概率的降低更为显著。
