Abstract: To investigate the impact of drivers distracted behavior on traffic flow of urban expressways, 26 driving volunteers were recruited to conduct a driving simulation experiment. The experiment simulated the driving states under congested conditions, including normal driving, text input, voice input, and hands-free calling, and analyzed the changes in the motion state of distracted vehicles compared to those driving normally. A simulation environment was built, and the vehicle motion state characteristics were taken as vehicle motion parameters to study the impact of distracted driving behavior on urban expressway traffic flow under different distraction ratios. The research results show that with the increase of distracted vehicles, the impact on expressway traffic flow has also increased. Taking the number of overtaking instances as an example, under 5% distraction, 10% distraction, and 15% distraction scenarios, the number of overtaking instances increases by 11.7%, 23.3%, and 28.0%, respectively, compared to normal driving. In addition, traffic density has a certain influence on vehicle speed and traffic flow. Under different density conditions, the impact of distracted driving on traffic flow varies. Under low-density conditions, the overall traffic flow exhibits high stability. When distracted driving occurs at 5%, 10% and 15%, the vehicle speed decreases by 12.8%, 13.8% and 17.9%, respectively. Under high-density conditions, the impact of distracted driving is weakened, with speed fluctuations remaining within 5.0%. While, under medium-density conditions, the impact of distracted driving is the most significant, resulting in speed reductions of 12.1%, 21.5%, and 40.1%, thereby increasing the vehicle instability.

Key words: traffic and transportation engineering; distracted behavior; vehicle motion state; distraction ratio; traffic flow

摘要： 为了探求城市快速路中驾驶人分心行为对交通流的影响，招募26名驾驶志愿者开展驾驶模拟实验，模拟拥挤流状态下正常驾驶、文字输入、语音输入和免提通话的驾驶状态，分析分心车辆相较于正常驾驶的车辆运动状态变化。搭建仿真环境，以车辆运动状态特征为车辆运动参数，研究不同分心比例下分心驾驶行为对城市快速路交通流的影响。研究结果表明：随着分心比例车辆的增加，对快速路交通流影响随之增加，以超车次数为例，正常驾驶、5%分心、10%分心和15%分心场景下，超车次数分别增加11.7%、23.3%和28.0%；交通密度在一定程度上影响车流速度和交通流量，在不同交通密度条件下，分心驾驶对交通流的影响存在差异，低密度状态下，整体交通流稳定性较高，5%、10%、15%分心驾驶时车速分别降低12.8%、13.8%和17.9%，高密度状态下分心驾驶影响被削弱，速度波动维持在5.0%以内，而中等密度状态下，分心驾驶影响最为显著，分别表现为车速降低12.1%、21.5%和40.1%，增强车辆行驶的不稳定性。

关键词: 交通运输工程；分心行为；车辆运动状态；分心比例；交通流