基于无人机航拍和交通冲突理论的城市交叉口安全评价方法

Safety Evaluation Method of Urban Intersection Using Unmanned Aerial Vehicle Imaging and Traffic Conflict Theory

现有城市交叉口安全评价方法多以交通事故数据统计为基础,方法存在数据收集时间较长、评价时间跨度大等不足,研究综合运用无人机航拍技术和交通冲突理论,对交叉口安全状况进行评价研究.首先,建立交叉口安全综合评价指标体系,体系由5个一级指标和15个二级指标构成.接着,提出基于交通冲突理论的城市交叉口层次分析-可拓安全评价模型,利用层次分析法的多层次性和可拓学的矛盾统一性从宏观角度综合评价城市交叉口的安全状况.其次,运用无人机航拍技术,获取全景的交叉口运行情况,提取交叉口渠化形式和交通冲突分布特征,并提出交叉口安全改善措施,运用微观仿真评估改善措施的有效性.最后,以天津市气象台路与平山道交叉口为例,运用无人机进行航拍,从航拍录像中提取交通冲突数据,运用层次分析-可拓安全评价模型,评估得出该交叉口的安全状况一般.另外,提出交通设计和交通信号控制的优化措施,运用VISSIM软件仿真验证,仿真结果显示:采用改善措施后,交叉口的行程时间减少11.02%,延误减少14.68%,排队长度减少13.64%,交叉口的运行效率得到了较好的提升.案例分析结果表明,提出的方法可用于城市交叉口的安全评价与优化.

The current methods of evaluating urban intersection safety always rely on massive traffic accident data,which have obvious disadvantages of long-time data collection,timeconsuming evaluation,and so on.In this context,both the unmanned aerial vehicle(UAV)imaging and traffic conflict theory are used to evaluate urban intersection safety in this study.First,an intersection safety evaluation index system is proposed,which is consisted of five first-level indexes and fifteen second-level indexes.Then,a hierarchy analysis and extended safety evaluation model based on traffic conflict theory is proposed.Next,the improvement measurements of urban intersection safety are presented,and the improvement effectiveness is verified by the micro-simulation.Finally,taking the intersection of Qixiangtai road and Pingshan road as an example,UAV was used to monitor the traffic situation and obtain the intersection broad-view videos,and a hierarchical analysis-extended model was proposed to evaluate the safety status of the given intersection,and the safety status was at the third level.Moreover,some safety improvements on traffic design and traffic signal control were summarized,and Vissim-simulation was conducted.The simulation results show that the travel time,delay time and queue length decrease by 11.02%,14.68%,and 13.64%respectively.The case study demonstrates that the proposed method can be used for urban intersection safety evaluation and optimization.