城市快速路X形交织区空间视域分析与几何线形优化设计研究

'X' shape weaving area has complex geometric alignment in urban expressway because of land restricted, which lead to low visibility in expressway space, easy to produce wrong visual space. High traffic flow in this area prone to traffic disorder, and with small self-recovery capacity. It's would spread disorder to the adjacent sections easily, and become the key node which influence the urban road network operational efficiency significantly. Through research on space visual threshold of weaving area, and the relationship between geometric alignment features, space visual perception and highway traffic capacity could be revealed, then the geometry alignment optimization design method can be put forward. There are several basic problems about this theme need be solved. Firstly, through field observation and theoretical analysis, research the geometry alignment characteristics and traffic operational characteristics of 'X' shape weaving area. Secondly, research on the space visual characteristic and dynamic visual features through visual perception principles and dynamic perspective analysis technology. Thirdly, the four-dimensional space visual mathematical model would established through space modeling technology and three-dimensional visual simulation technology. Fourthly, through comprehensive use of field observation, natural driving experiment, driving simulation experiment and conflict analysis theory, the traffic conflict calculate method of weaving area would put forward, and the relational model between establish weaving area horizon four-dimensional space visual model parameters, traffic capacity and safety performance would established. Lastly, the optimization design method of geometry alignment would established through comprehensive use of model research results, which could provide theoretical guidance for geometry alignment design of weaving area.

城市快速路“X”形交织区受用地限制几何线形复杂，道路空间可视性低，易产生空间错视觉；交通流量大易发生交通紊乱，自恢复能力小，易波及到毗邻路段交织区，是影响城市快速路网运行效率的关键节点。因此，有必要通过交织区空间视域研究，揭示交织区几何特征、空间视觉感知与路段通行能力之间的相互关系，提出交织区几何线形组合优化设计方法。围绕这一主题需解决的基础性问题为：通过现场观测、理论分析，研究城市快速路X形交织区几何参数及交通运行特性；运用视觉感知原理、动态视觉分析技术研究空间视域及动态视觉特性；利用空间建模与三维视图仿真技术建立交织区四维空间视域数学模型；综合现场观测、自然驾驶试验、驾驶模拟实验与冲突分析理论，研究提出交织区交通冲突计算方法，建立交织区空间视域参数与通行能力、安全性能的关系模型。最后，综合运用模型研究成果，建立几何线形组合优化设计方法，为交织区几何线形优化设计提供理论指导。

城市快速路“X”形交织区受用地限制几何线形复杂，道路空间可视性低，易产生空间错视觉；交通流量大易发生交通紊乱，自恢复能力小，易波及到毗邻路段交织区，是影响城市快速路网运行效率的关键节点。因此，有必要对交织区进行研究，揭示交织区几何特征、交通运行与行车安全性之间的相互关系，提出交织区几何线形组合优化设计方法。本项目采用现场观测、理论分析、自然驾驶、驾驶模拟与交通仿真等手段开展研究。调研了城市快速路交织区线形与交通组织管控措施，选择典型城市快速路X形交织区进行交通检测数据采集与分析，通过自然驾驶实验对车辆在交织区的运行状况进行了进一步调研；基于几何线形三维模型构建了城市快速路X形交织区四维空间模型；基于八自由度驾驶模拟实验平台制作了仿真场景进行驾驶模拟试验，通过VISSIM开展了交通仿真实验，采集分析了驾驶模拟实验与交通仿真数据，提出了交织区几何线形特性、交通流状况与安全性能相互关系的量化方法；确定了X形交织区几何线形优化设计的关键参数，建立交织区几何线形组合的优化设计方法，并根据安全变道约束条件、提出了最小变道距离计算方法，提出了基于有效安全间隙的交织区长度优化方法。研究成果可为城市快速路交织区安全性能分析与几何线形优化设计提供技术支撑。