Jeong Eunbi, Oh Cheol
Hanyang University Erica Campus, Department of Transportation and Logistics Engineering, 55 Hanyangdaehak-ro, Sangnok-gu, Ansan 426-791, Republic of Korea.
Accid Anal Prev. 2017 Mar;100:85-96. doi: 10.1016/j.aap.2017.01.015. Epub 2017 Jan 24.
Advanced vehicle safety systems have been widely introduced in transportation systems and are expected to enhance traffic safety. However, these technologies mainly focus on assisting individual vehicles that are equipped with them, and less effort has been made to identify the effect of vehicular technologies on the traffic stream. This study proposed a methodology to assess the effectiveness of active vehicle safety systems (AVSSs), which represent a promising technology to prevent traffic crashes and mitigate injury severity. The proposed AVSS consists of longitudinal and lateral vehicle control systems, which corresponds to the Level 2 vehicle automation presented by the National Highway Safety Administration (NHTSA). The effectiveness evaluation for the proposed technology was conducted in terms of crash potential reduction and congestion mitigation. A microscopic traffic simulator, VISSIM, was used to simulate freeway traffic stream and collect vehicle-maneuvering data. In addition, an external application program interface, VISSIM's COM-interface, was used to implement the AVSS. A surrogate safety assessment model (SSAM) was used to derive indirect safety measures to evaluate the effectiveness of the AVSS. A 16.7-km freeway stretch between the Nakdong and Seonsan interchanges on Korean freeway 45 was selected for the simulation experiments to evaluate the effectiveness of AVSS. A total of five simulation runs for each evaluation scenario were conducted. For the non-incident conditions, the rear-end and lane-change conflicts were reduced by 78.8% and 17.3%, respectively, under the level of service (LOS) D traffic conditions. In addition, the average delay was reduced by 55.5%. However, the system's effectiveness was weakened in the LOS A-C categories. Under incident traffic conditions, the number of rear-end conflicts was reduced by approximately 9.7%. Vehicle delays were reduced by approximately 43.9% with 100% of market penetration rate (MPR). These results imply that from the perspective of traffic operations and control to address the safety and congestion issues of a traffic stream, smarter management strategies that consider both traffic conditions and MPR are required to fully exploit the effectiveness of the AVSS in the field.
先进的车辆安全系统已在交通系统中广泛应用，有望提高交通安全。然而，这些技术主要侧重于辅助配备它们的单个车辆，而在确定车辆技术对交通流的影响方面所做的工作较少。本研究提出了一种评估主动车辆安全系统（AVSS）有效性的方法，该系统是预防交通事故和减轻伤害严重程度的一项很有前景的技术。所提出的AVSS由纵向和横向车辆控制系统组成，这与美国国家公路交通安全管理局（NHTSA）提出的2级车辆自动化相对应。从减少碰撞可能性和缓解拥堵方面对所提出技术的有效性进行了评估。使用微观交通模拟器VISSIM来模拟高速公路交通流并收集车辆操纵数据。此外，利用外部应用程序接口VISSIM的COM接口来实现AVSS。使用替代安全评估模型（SSAM）得出间接安全措施，以评估AVSS的有效性。选择韩国45号高速公路上洛东江和仙山互通之间16.7公里的高速公路路段进行模拟实验，以评估AVSS的有效性。每个评估场景总共进行了五次模拟运行。在非事故条件下，在服务水平（LOS）D交通条件下，追尾和变道冲突分别减少了78.8%和17.3%。此外，平均延误减少了55.5%。然而，在LOS A - C类别中，该系统的有效性有所减弱。在事故交通条件下，追尾冲突数量减少了约9.7%。在市场渗透率（MPR）为100%的情况下，车辆延误减少了约43.9%。这些结果表明，从交通运营和控制的角度来解决交通流的安全和拥堵问题，需要考虑交通状况和MPR的更智能管理策略，以充分发挥AVSS在实际应用中的有效性。
