基于道路结构特征识别的城市交通状态空间自相关分析

 城市道路交通状态具有空间自相关特征。路段交通状态的变化会很快影响到邻近路段,导致一定空间范围内路段的交通状态发生改变。揭示城市交通状态的空间自相关特征,对交通规划、交通控制与诱导具有重要意义。然而,受到城市路网空间结构和道路拓扑特征的影响,城市道路交通状态的空间自相关并非各向同性,也并非均匀地向上下游扩散,而是有选择性地集中在部分邻近路段上。因此,仅考虑路段地理空间下的上下游邻近性,难以全面度量路段间交通状态的相互影响,识别出交通状态空间相关性强的道路集合。本文借鉴复杂网络分析方法,定量化分析了城市路网的模块化与层次性特征,利用城市路段在空间上的聚集特征和路段在网络中拓扑角色的差异,提出了一种新的交通状态自相关路段邻近性判别规则,即空间邻近且拓扑等价规则,以此规则实现交通状态空间相关路段聚类过程,更好地揭示城市路段之间的交通状态空间相关性。

Spatial Autocorrelation of Urban Road Traffic Based on Road Network Characterization

Urban road traffic is spatially autocorrelated. The change of traffic on certain road will quickly affect the traffic on nearby roads, which will alter the overall traffic status within a neighborhood. Revea-ling the spatial autocorrelation structure in urban road traffic is important for traffic planning, traffic con-trolling and traffic guidance. The traffic interaction between neighboring roads is not isotropy. The traffic change on certain road does not equally spread to each spatially adjacent road, but concentrate on some of them. Thus only using spatial adjacency to define adjacent roads cannot well reveal the spatial autocorrela-tion in urban road traffic. Recent research has proved that the dynamic flow on networks highly depend on the structure of networks. Characterizing the structure of urban road network is essential to reveal the spatial autocorrelation in urban road traffic. The aim of this research is to reveal the spatial autocorrela- tion of urban road traffic based on road network characterization. We first investigate the modular charac-ter and hierarchal feature of urban road network quantitatively. The modulars in road network are defined as a group of closely connected neighboring road segments and identified by community detection algo-rithm from complex network theory. The hierarchal feature of urban road network helps to determine the structural importance of road segments. Topological roles are defined based on the structural importance of road segment. Then we provide a novel approach to define adjacent road segments based on the topolog-ical roles in spatially adjacent road segments. Two road segments defined as adjacent road segments not only locate in a nearby neighborhood but also have the same topological roles. A set of adjacent roads con-stitute a spatial related set. Experiment results on the road network of Beijing imply that the spatial relat-ed sets identified by the proposed approach can capture the spatial autocorrelation structure of urban road traffic.