Wang Ying, Tu Huizhao, Sze N N, Li Hao, Ruan Xin
Key Laboratory of Road and Traffic Engineering of the Ministry of Education, Tongji University, 4800 Cao'an Road, Shanghai 201804, China.
Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China.
J Safety Res. 2022 Feb;80:1-13. doi: 10.1016/j.jsr.2021.09.008. Epub 2021 Sep 28.
Vehicle weight is deterministic to the impact force in collision, and thus the injury risk of vehicle occupants. In China, involvement of heavy vehicles in overall and fatal crashes are prevalent, even though heavy vehicles only constitute a small proportion of overall registered motor vehicles. However, vehicle weight is rarely considered in the existing traffic conflict risk prediction and assessment models because of the unavailability of required data.
Novel risk indicators for the diagnosis of traffic conflict risk map, considering the effect of vehicle weight, are proposed, with the advantage of comprehensive traffic flow characteristics and vehicle weight data using Weigh-in-Motion (WIM) technique. Weight-incorporated risk level (WRL) and weight integrated risk level (WIRL) are established to quantify the traffic conflict risk, at an instant and over a specified time period, respectively, by extending the conventional traffic conflict risk measures including time-to-collision (TTC) and modified potential collision energy (PCE). Then, a microscopic traffic simulation model is adopted to estimate the traffic conflict risk map along a highway segment that has partial lane closure. The traffic conflict risk performances, between the risk indicators with and without considering the vehicle weight, are compared.
The traffic conflict risks estimated using conventional risk indicators without considering the vehicle weight are generally lower than that based on WRL and WIRL. The difference is more profound when the proportion of heavy vehicles in the traffic stream increases.
The finding is indicative to remedial engineering measures including variable message sign, speed limit, and ramp metering that can mitigate the real-time crash risks on highways, especially in adverse environmental and weather conditions, with due consideration of vehicle composition and crash worthiness of vehicles.
车辆重量决定碰撞时的冲击力，进而影响车内人员的受伤风险。在中国，重型车辆在整体和致命撞车事故中占比很高，尽管重型车辆在注册机动车总数中所占比例较小。然而，由于所需数据难以获取，现有交通冲突风险预测和评估模型很少考虑车辆重量。
提出了考虑车辆重量影响的新型交通冲突风险地图诊断风险指标，其优势在于利用动态称重（WIM）技术综合了交通流特征和车辆重量数据。通过扩展传统交通冲突风险度量指标，包括碰撞时间（TTC）和修正潜在碰撞能量（PCE），分别建立了即时和特定时间段内量化交通冲突风险的含重量风险水平（WRL）和重量综合风险水平（WIRL）。然后，采用微观交通仿真模型来估计部分车道封闭的高速公路路段的交通冲突风险地图。比较了考虑和不考虑车辆重量的风险指标之间的交通冲突风险表现。
使用不考虑车辆重量的传统风险指标估计的交通冲突风险通常低于基于WRL和WIRL的风险。当交通流中重型车辆的比例增加时，差异更为显著。
该研究结果表明，在适当考虑车辆组成和车辆防撞性的情况下，包括可变情报板、限速和匝道控制在内的补救工程措施可以降低高速公路上的实时撞车风险，尤其是在不利的环境和天气条件下。
