Introduction: Driver’s evasive action is closely associated with collision risk in a critical traffic event. To quantify collision risk, surrogate safety measures (SSMs) have been estimated using vehicle trajectories. However, vehicle trajectories cannot clearly capture presence and time of driver’s evasive action. Thus, this study determines the driver’s evasive action based on his/her use of accelerator and brake pedals, and analyzes the effects of the driver’s evasive action time (i.e., duration of evasive action) on rear-end collision risk. Method: Fifty drivers’ car-following behavior on a freeway was observed using a driving simulator. An SSM called “Deceleration Rate to Avoid Crash (DRAC)” and the evasive action time were determined for each driver using the data from the driving simulator. Each driver tested two traffic scenarios – Cars and Trucks scenarios where conflicting vehicles were cars and trucks, respectively. The factors related to DRAC were identified and their effects on DRAC were analyzed using the Generalized Linear Models and random effects models. Results: DRAC decreased with the evasive action time and DRAC was closely related to drivers’ gender and driving experience at the road sections where evasive action to avoid collision was required. DRAC was also significantly different between Cars and Trucks scenarios. The effect of the evasive action time on DRAC varied among different drivers, particularly in the Trucks scenario. Conclusions: Longer evasive action time can significantly reduce crash risk. Driver characteristics are more closely related to effective evasive action in complex driving conditions. Practical Applications: Based on the findings of this study, driver warning information can be developed to alert drivers to take specific evasive action that reduces collision risk in a critical traffic event. The information is likely to reduce the variability of the driver’s evasive action and the speed variations among different drivers.

简介：驾驶员的规避行为与关键交通事件中的碰撞风险密切相关。为了量化碰撞风险，已经使用车辆轨迹估计了替代安全措施（SSM）。然而，车辆轨迹不能清楚地捕捉到驾驶员回避行为的存在和时间。因此，本研究根据驾驶员对油门踏板和制动踏板的使用情况来确定驾驶员的回避动作，并分析驾驶员的回避动作时间（即回避动作的持续时间）对追尾风险的影响。方法：使用驾驶模拟器观察了 50 名司机在高速公路上的跟车行为。使用来自驾驶模拟器的数据为每个驾驶员确定称为“避免碰撞的减速率 (DRAC)”的 SSM 和规避动作时间。每个司机测试了两种交通场景——汽车和卡车场景，其中冲突的车辆分别是汽车和卡车。确定了与 DRAC 相关的因素，并使用广义线性模型和随机效应模型分析了它们对 DRAC 的影响。结果：DRAC随着规避动作时间的增加而降低，在需要采取规避动作避免碰撞的路段，DRAC与驾驶员的性别和驾驶经验密切相关。汽车和卡车场景之间的 DRAC 也有显着差异。躲避动作时间对 DRAC 的影响因不同的驾驶员而异，尤其是在卡车场景中。结论：更长的规避动作时间可以显着降低碰撞风险。驾驶员特征与复杂驾驶条件下的有效规避行为更密切相关。实际应用：根据这项研究的结果，可以开发驾驶员警告信息，以提醒驾驶员采取特定的规避措施，以降低关键交通事件中的碰撞风险。该信息可能会减少驾驶员的规避动作的可变性以及不同驾驶员之间的速度变化。