Othman Sarbaz, Thomson Robert, Lannér Gunnar
Department of Applied Mechanics, Chalmers University of Technology, Gothenburg, Sweden Swedish National Road and Transport Research Institute, Gothenburg, Sweden Department of Civil and Environmental Engineering, Chalmers University of Technology, Gothenburg, Sweden.
Ann Adv Automot Med. 2010;54:253-64.
It is well known that crashes on horizontal curves are a cause for concern in all countries due to the frequency and severity of crashes at curves compared to road tangents. A recent study of crashes in western Sweden reported a higher rate of crashes in right curves than left curves. To further understand this result, this paper reports the results of novel analyses of the responses of vehicles and drivers during negotiating and overtaking maneuvers on curves for right hand traffic. The overall objectives of the study were to find road parameters for curves that affect vehicle dynamic responses, to analyze these responses during overtaking maneuvers on curves, and to link the results with driver behavior for different curve directions. The studied road features were speed, super-elevation, radius and friction including their interactions, while the analyzed vehicle dynamic factors were lateral acceleration and yaw angular velocity. A simulation program, PC-Crash, has been used to simulate road parameters and vehicle response interaction in curves. Overtaking maneuvers have been simulated for all road feature combinations in a total of 108 runs. Analysis of variances (ANOVA) was performed, using two sided randomized block design, to find differences in vehicle responses for the curve parameters. To study driver response, a field test using an instrumented vehicle and 32 participants was reviewed as it contained longitudinal speed and acceleration data for analysis. The simulation results showed that road features affect overtaking performance in right and left curves differently. Overtaking on right curves was sensitive to radius and the interaction of radius with road condition; while overtaking on left curves was more sensitive to super-elevation. Comparisons of lateral acceleration and yaw angular velocity during these maneuvers showed different vehicle response configurations depending on curve direction and maneuver path. The field test experiments also showed that drivers behave differently depending on the curve direction where both speed and acceleration were higher on right than left curves. The implication of this study is that curve direction should be taken into consideration to a greater extent when designing and redesigning curves. It appears that the driver and the vehicle are influenced by different infrastructure factors depending on the curve direction. In addition, the results suggest that the vehicle dynamics response alone cannot explain the higher crash risk in right curves. Further studies of the links between driver, vehicle, and highway characteristics are needed, such as naturalistic driving studies, to identify the key safety indicators for highway safety.
众所周知，由于与道路直线段相比，弯道处事故的频率和严重程度较高，水平弯道上的撞车事故在所有国家都是一个令人担忧的问题。瑞典西部最近一项关于撞车事故的研究报告称，右弯道的撞车率高于左弯道。为了进一步理解这一结果，本文报告了针对右手交通情况下车辆和驾驶员在弯道上进行谈判和超车操作时的反应进行的新颖分析结果。该研究的总体目标是找到影响车辆动态反应的弯道道路参数，分析弯道上超车操作期间的这些反应，并将结果与不同弯道方向的驾驶员行为联系起来。所研究的道路特征包括速度、超高、半径和摩擦力及其相互作用，而分析的车辆动态因素是横向加速度和偏航角速度。使用了一个模拟程序PC-Crash来模拟弯道中的道路参数和车辆反应相互作用。针对总共108次运行中的所有道路特征组合模拟了超车操作。使用双侧随机区组设计进行方差分析（ANOVA），以找出弯道参数在车辆反应方面的差异。为了研究驾驶员的反应，对一项使用仪器车辆和32名参与者的现场测试进行了审查，因为该测试包含纵向速度和加速度数据以供分析。模拟结果表明，道路特征对右弯道和左弯道超车性能的影响不同。右弯道超车对半径以及半径与道路状况的相互作用敏感；而左弯道超车对超高更敏感。这些操作期间横向加速度和偏航角速度的比较表明，根据弯道方向和操作路径，车辆反应配置不同。现场测试实验还表明，驾驶员的行为因弯道方向而异，右弯道上的速度和加速度均高于左弯道。这项研究的意义在于，在设计和重新设计弯道时应更大程度地考虑弯道方向。似乎驾驶员和车辆根据弯道方向受到不同的基础设施因素影响。此外，结果表明仅车辆动态反应无法解释右弯道较高的撞车风险。需要进一步研究驾驶员、车辆和公路特征之间的联系，例如自然驾驶研究，以确定公路安全的关键安全指标。
