Department of Road Safety, Swedish Transport Administration, Borlänge, Sweden.
Department of Mechanics and Maritime Sciences, Chalmers University of Technology, Gothenburg, Sweden.
Traffic Inj Prev. 2021;22(2):139-146. doi: 10.1080/15389588.2020.1869224. Epub 2021 Feb 8.
The objective of this study is to estimate the potential safety benefits of Emergency Lane Keeping (ELK) and Autonomous Emergency Steering (AES) systems with precise and reliable lateral positioning.
The material comprised in-depth studies of fatal road crashes in Sweden in 2017. Crashes resulting in passenger car occupant fatality ( = 114) were included; single vehicle ( = 60) and head-on ( = 31), intersection ( = 9), rear-end ( = 5), overtaking ( = 5), animal ( = 1), other ( = 1, U-turn), and train ( = 2). Additionally, fatal collisions between motor vehicles and vulnerable road users (VRUs) were included; pedestrians ( = 36), cyclists/moped users ( = 15), and motorcyclists ( = 17). A case-by-case analysis was conducted to identify crashes potentially prevented by ELK and AES with precise (within 0.1 m accuracy) and reliable lateral positioning. The identified crashes potentially avoided by ELK systems involved unintentional drift-out-of-lane on roads with posted speed limits of ≥70 km/h (43 mph). For comparison, the same material was used to identify the potential safety benefits of the more traditional lane departure warning (LDW) and Lane Keeping Assist (LKA) systems without enhanced lateral positioning. Crashes potentially avoided by LDW/LKA occurred on roads with visible lane markings and without rumble strips on the departure side while ELK with enhanced lateral positioning is not reliant on lane markings. Collisions potentially avoided by AES occurred on roads with sufficient escape zones and road friction.
The study shows that ELK systems with enhanced lateral positioning could potentially avoid 33 - 45 (36 - 49%) out of 91 head-on and single car crashes resulting in passenger car occupant fatality, which corresponds to a further 18% (5/28) compared to traditional lane support (LDW/LKA) without enhanced lateral positioning. The improved lane keeping addresses crashes involving absent or nonvisible lane markings that are covered by snow. Furthermore, the study shows that the evasive steering features of AES systems with enhanced lateral positioning could potentially prevent 28 (54%) out of 52 collisions resulting in passenger car occupant fatalities (i.e., head-on, intersection, rear-end, overtaking, and animal collision). Additionally, AES with enhanced lateral positioning could potentially prevent 16 (31%) out of 51 collisions between motor vehicles and vulnerable road users resulting in fatally injured pedestrians, cyclists or moped users. The total potential safety benefits of AES include both lane keeping and evasive steering features including lane escaping. The study identified that the total number of crashes potentially avoided by AES corresponds to 42% out of all crashes resulting in passenger car occupant fatalities ( = 48/114).
This is a first attempt to identify and quantify the increase in potential safety benefits, based on the assumption that robust lateral vehicle positioning has been applied to lane keeping as well as lane escaping. In addition to the potentially increased number of prevented crashes compared to traditional lane support, a robust lateral positioning system may have the potential to improve the redundancy in positioning systems. Previous research suggests several techniques to improve lateral vehicle positioning. However, further research is required, including testing for implementation of adequately improved lateral vehicle awareness to establish which techniques are appropriate.
本研究旨在评估具有精确和可靠横向定位功能的紧急车道保持（ELK）和自动驾驶转向（AES）系统的潜在安全效益。
本研究的资料包括对 2017 年瑞典致命道路事故的深入研究。包括乘用车乘客死亡（ = 114）的事故；单车事故（ = 60）和正面碰撞（ = 31）、路口（ = 9）、追尾（ = 5）、超车（ = 5）、动物（ = 1）、其他（ = 1，掉头）和火车（ = 2）。此外，还包括涉及与弱势道路使用者（VRU）的致命碰撞的事故；行人（ = 36）、自行车/轻便摩托车使用者（ = 15）和摩托车手（ = 17）。对每起事故进行了逐一分析，以确定潜在的 ELK 和 AES 系统可以通过精确（精度在 0.1 m 以内）和可靠的横向定位来避免的事故。ELK 系统潜在避免的事故涉及在限速≥70 km/h（43 mph）的道路上无意偏离车道。相比之下，使用相同的材料来确定传统车道偏离警告（LDW）和车道保持辅助（LKA）系统在没有增强的横向定位时的潜在安全效益。潜在避免的 LDW/LKA 事故发生在有可见车道标记且离开侧没有隆起条的道路上，而具有增强横向定位的 ELK 则不依赖于车道标记。潜在避免的 AES 事故发生在有足够的避让区和路面摩擦的道路上。
研究表明，具有增强横向定位的 ELK 系统可能潜在避免 91 起正面碰撞和单车碰撞事故中的 33-45 起（36-49%），导致乘用车乘客死亡，这与传统车道支持（LDW/LKA）相比进一步增加了 18%（5/28），传统车道支持（LDW/LKA）没有增强的横向定位。改进的车道保持功能解决了涉及不存在或不可见车道标记的事故，这些车道标记被积雪覆盖。此外，研究表明，具有增强横向定位的 AES 系统的避险转向功能可能潜在避免 52 起导致乘用车乘客死亡的事故中的 28 起（54%）（即正面碰撞、路口、追尾、超车和动物碰撞）。此外，具有增强横向定位的 AES 可能潜在避免 51 起涉及机动车和弱势道路使用者的事故中的 16 起（31%），导致行人、骑自行车或骑轻便摩托车的人受重伤。AES 的总潜在安全效益包括车道保持和避险转向功能，包括车道逃离。研究确定，AES 潜在避免的事故总数占乘用车乘客死亡事故总数（ = 48/114）的 42%。
这是首次尝试根据假设的横向车辆定位具有鲁棒性的假设，确定并量化潜在安全效益的增加，该假设适用于车道保持和车道逃离。除了与传统车道支持相比，潜在避免的事故数量增加之外，强大的横向定位系统还有可能提高定位系统的冗余度。先前的研究提出了几种改进横向车辆定位的技术。然而，需要进一步研究，包括对足够改进的横向车辆感知的实施进行测试，以确定哪些技术是合适的。
