title: Development of a variable speed limit strategy to reduce secondary collision risks during inclement weathers.
abstract: Inclement weather reduces traveler's sight distance and increases vehicle's stopping distance. Once a collision occurred during inclement weather and resulted in a slow traffic, approaching vehicles may not have adequate time to make emergency responses to the hazardous traffic, resulting in increased potentials of secondary collisions. The primary objective of this study is to develop a control strategy of variable speed limits (VSL) to reduce the risks of secondary collisions during inclement weathers. By analyzing the occurrence condition of secondary collision, the VSL strategy is proposed to dynamically adjust the speed limits according to the current traffic and weather conditions. A car-following model is modified to simulate the vehicle maneuvers with the VSL control. Two surrogate safety measures, based on the time-to-collision notion, are used to evaluate the control effects of VSL. Five weather scenarios are evaluated in simulation. The results show that the VSL strategy effectively reduces the risks of secondary collisions in various weather types. The time exposed time-to-collision (TET) is reduced by 41.45%-50.74%, and the time integrated time-to-collision (TIT) is reduced by 38.19%-41.19%. The safety effects are compared to those with a previous VSL strategy. The results show that in most cases our strategy outperforms the previous one. We also evaluate how driver's compliance to speed limit affects the effectiveness of VSL control.
authors.affiliation: Jiangsu Key Laboratory of Urban ITS, Southeast University, 2 Si Pai Lou, Nanjing 210096, China; Jiangsu Province Collaborative Innovation Center of Modern Urban Traffic Technologies, 2 Si Pai Lou, Nanjing 210096, China. Electronic address: lizhibin@seu.edu.cn.
authors.forename: Zhibin
authors.initials: Z
authors.lastname: Li
authors.affiliation: Jiangsu Key Laboratory of Urban ITS, Southeast University, 2 Si Pai Lou, Nanjing 210096, China; Jiangsu Province Collaborative Innovation Center of Modern Urban Traffic Technologies, 2 Si Pai Lou, Nanjing 210096, China. Electronic address: liye@seu.edu.cn.
authors.forename: Ye
authors.initials: Y
authors.lastname: Li
authors.affiliation: Jiangsu Key Laboratory of Urban ITS, Southeast University, 2 Si Pai Lou, Nanjing 210096, China; Jiangsu Province Collaborative Innovation Center of Modern Urban Traffic Technologies, 2 Si Pai Lou, Nanjing 210096, China. Electronic address: pan_liu@hotmail.com.
authors.forename: Pan
authors.initials: P
authors.lastname: Liu
authors.affiliation: Jiangsu Key Laboratory of Urban ITS, Southeast University, 2 Si Pai Lou, Nanjing 210096, China; Jiangsu Province Collaborative Innovation Center of Modern Urban Traffic Technologies, 2 Si Pai Lou, Nanjing 210096, China. Electronic address: wangwei@seu.edu.cn.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.affiliation: Jiangsu Key Laboratory of Urban ITS, Southeast University, 2 Si Pai Lou, Nanjing 210096, China; Jiangsu Province Collaborative Innovation Center of Modern Urban Traffic Technologies, 2 Si Pai Lou, Nanjing 210096, China. Electronic address: iamxcc1@gmail.com.
authors.forename: Chengcheng
authors.initials: C
authors.lastname: Xu
mesh_terms: D000063:Accidents, Traffic / Q000517:prevention & control*; D001334:Automobile Driving / Q000331:legislation & jurisprudence*; D003198:Computer Simulation; D004779:Environment Design; D006801:Humans; D014887:Weather
keywords: Inclement weather; Safety; Secondary collision; Strategy; Variable speed limit