基于路网数据和复杂图论的中国城市交通布局评价

城市化的快速发展推动了我国城市道路网的不断扩张和发展.城市道路网是一个动态、开放、自组织的空间复杂网络,构成了城市的结构框架,研究城市道路网的结构特征对路网规划和城市建设有着重要的应用价值.在国内城市道路网络结构特征的相关研究中,很少有学者基于道路走向的视角对整个城市路网结构进行研究,也缺少对全国主要城市路网的整体性评...

Delineating China's Urban Traffic Layout by Integrating Complex Graph Theory and Road Network Data

The rapid development of urbanization has promoted China's urban road network's continuous expansion and growth. The urban road network is a dynamic, open, and self-organized spatial complex network, which constitutes a city's structural framework. The study on urban road networks' structural characteristics can provide a significant application value for road network planning and urban construction. In the related studies of the structural characteristics of urban road networks, few scholars have paid attention to the whole urban road network structure from the perspective of road alignment in China. Besides, recent studies lack an overall evaluation on the road network of major cities in China. In this paper, 49 cities, including the first- and second-tier and first-tier new cities in China, are selected as study areas and the urban road network data in February 2020 are taken as experimental data. Firstly, we use the graph theory and rose diagrams to visualize the road network's directional characteristics in 49 cities. The complex structure of the urban road network is qualitatively analyzed. Then, we select five road network indicators including the maximum ratio R, the road primacy degree S, the ratio over threshold T, the orientation-order φ, and the road network density δ. Based on the five indicators, cluster analysis is carried out for the road networks of 49 cities in this paper. And the characteristics of the spatial distribution of urban road network in China are explored. The results show that the north-south and east-west roads are the main alignment of urban roads in China. Because of the influence of terrain, some cities plan routes along the direction, which is favorable to traffic and resident's living. Based on the clustering of road network indicators, four types of the urban road network are obtained, including cross orthogonal type, cross to windmill type, windmill to arc type, and mixed complex type. There are significant differences among four types of the urban road network in directional characteristics highlighted in complexity and order. In view of the spatial distribution of road network types, road networks of cross orthogonal type and cross to windmill type are mainly distributed in China's inland areas. In contrast, road networks of the windmill to arc type and mixed complex type are mainly distributed in coastal areas. This paper explores the current traffic layout in major cities in China by analyzing the characteristics of road network's distribution in the first- and second-tier and first-tier new cities in China. This study can provide a reference for road planning and optimization of road network layout in new urban districts.