Hazard modeling for next-generation multi-vehicle accidents and development of biofeedback console

城市地下快速路在解决许多现有交通问题方面具有很大的潜力，但也会给交通安全带来未知的风险。由于隧道的封闭空间，特别是在深埋地下的隧道中，车辆事故对道路基础设施和人员生命的损害比室外道路更严重。因此，既要预防单车事故，也要考虑多车事故的安全对策，因为多车事故的危害更大。我们进行了一项独特的虚拟现实（VR）驾驶实验，其中多个受试者可以在同一道路空间同时驾驶。在这个实验中，我们收集了由单一车辆事故引起的多车辆事故的微观驾驶数据。数据分析的结果揭示了导致多车事故发生的一些重要因素。利用驾驶模拟器在城市地下高速公路上进行了生命反应（=唤醒水平）反馈实验，研究了将降低唤醒水平明确告知驾驶员的反馈方法。通过生物反馈系统，在驾驶员感到困倦之前告知驾驶员声压级的降低可以抑制声压级的降低。困倦后，SPL降低的信息不影响困倦的解除。这表明生物反馈系统对于提高车辆驾驶员的安全性是可行的。

Underground urban expressways which have great potential to settle many existing transportation-related problems may pose unknown risks regarding traffic safety. Vehicle accident in tunnel can more seriously damage road infrastructure and human life than outside roads because of its closed space especially in deep underground road. Therefore, it is important to consider the safety countermeasure for preventing not only a single-vehicle accident but also multi-vehicle accidents which are more damaging. We conducted a unique driving experiment with virtual reality (VR) where the multiple subjects can drive simultaneously in the same roadway space. With this experiment, we collected the microscopic driving data of multi-vehicle accidents that originated in a single-vehicle accident. The results of data analysis reveal some important factors causing the occurrence of multi-vehicle accidents.The vital reaction (= arousal level) feedback experiments were carried out in the underground urban expressway using the driving simulator to study the feedback method in which the reduction arousal level was informed of drivers surely. The reduction of SPL would be suppressed by informed it before a vehicle driver felt sleepy with the bio-feedback system. And after he felt sleepy, the information of reduction of SPL doesn't influence the untying the sleepiness.This shows the bio-feedback system is available to safety improvement of vehicle drivers.