基于SEM的双车道公路超车行为安全评价

为提高驾驶人在双车道公路上超车的安全性,基于tau理论适应性分析,提出超车过程中驾驶人不仅根据tau线索估计避碰时间,也利用距离、速度、加速度等判断超车是否安全的试验假设。招募12名受试者,应用驾驶模拟系统试验平台,依据试验假设采集12个与超车行为有关的驾驶行为数据,对其进行无量纲化处理,并利用Bootstrap法对数据进行扩增。结合驾驶行为问卷得分,利用AMOS软件,建立超车行为安全评价的结构方程模型。通过对初始假设模型进行多次修正与评价,得到影响超车行为安全的3个驾驶行为参数。结果表明,超车车辆在超车并道后的速度、与前导车之间的避碰时间及与对向车辆之间的避碰时间这3个驾驶行为参数可作为超车行为安全评价的有效指标。

Safety evaluation for the overtaking behavior on the two-lane highway based on the structural equation model

To improve the drivers' overtaking safety in the two-lane highway,the present paper is inclined to suppose that in the process of overtaking,the drivers should not only estimate the time to collision (TTC) on a basis of tau clue,but also take the advantages of the distance,speed,acceleration and determine whether it is safe to overtake the other vehicles based on the theory of tau adaptability analysis and choice of acceleration and other parameters.It is just on the above said hypothesis that we have made a driving simulated experiment in hoping to acquire the 12 driving behavior parameters related to the aforementioned overtaking behaviors.For further data analysis,it would be necessary to divide the driving behavior into 12 subjective parameters to be recorded in the experiment process while doing the dimensionless pretreatment and expanded by the bootstrap method in advance,so as to establish a structural equation model (SEM) of overtaking safety with the help of the scores of driving behavior questionnaire based on AMOS.And,next,it would be possible to derive the three observed variables that may affect and represent the overtaking safety by using the multiple modification and evaluation of the initial assumption model.The results of our simulation and experiment indicate that (1) The overtaking behavior safety can be worked out by the following 3 effective indicators,that is,the time for completing the merge,the speed of the overtaking vehicle,the time for collision with the leading vehicle,with the time of collision with the oncoming vehicle;(2) The speed of the overtaking vehicle should be more in charge of the overtaking behavior,for its overtaking speed serves as the dominant factor influencing the traffic safety.What is more,as compared with the time for the likely collision with the oncoming vehicle and the time for collision,the driving speed of the leading vehicle indicates and proves to be more affecting the driving transportation safety;(3) When the merging action is over,the difference that represents the overtaking behavior for the collision with the leading vehicle and for the time of collision with the oncoming vehicle may not be statistically significant,that is to say,the two vehicles may have the same significant effect on the overtaking behavior.More emphatically speaking,the nearer and closer the two vehicles are becoming,the more unsafe or dangerous their overtaking behaviors would be.And,in turn,the negative relation affecting the transportation safety between the two vehicles should be in accord with the status-in-situ investigation case study samples.