Analysis On The Influence Of Road Network Structure On Conventional Public Transport System

Urbanization, motorization and informatization have brought the rapid development of city, at the same time led to serious traffic problems, which not only has brought a lot of inconvenience to people’s life and work, but also affected the city’s economic and social development. To alleviate traffic congestion and solve the social problems caused by it, the government put forward the "bus priority" strategy. Based on this, public transport systems,especially conventional public transport systems have rapidly developed. The road network as the skeleton and support of the conventional public transport system in the city, is regarded as the important factor which affect the distribution of the conventional bus lines and passengers flow. A structurally reasonable, fully functional and capacity sufficient road network system is an important basic condition for the sustainable development of the conventional public transportation system. Therefore, it is necessary to determine the method and index of the structure of road network, and analyze it’s influence on the conventional public transportation system, as well as provide the theoretical basis and technical support for the urban road network planning for public transportation.In view of this, this paper firstly build road network structure analysis model: the stroke(the continuous set of the road sections in the direction) is used as the analysis unit of the road network structure, the route map is abstracted as the dot graph, and then the connection matrix among the routes is obtained. Based on this calculation, the index center degree of the importance of the route in the network structure is described, and the degree of index aggregation is described. Based on the degree of clustering and road network density, the network structure index which describe "centralized" or "decentralized" features of the layout structure of the road network is defined, and the index is revised based on the land type.Secondly, introduced the characteristics of conventional public transportation system.Based on the domestic, foreign research and the operability of the data, the distribution of bus network density, bus mileage and bus passenger turnover are selected as indexes to describe the characteristics of conventional public transportation system. Based on the AVL data and IC card data of the conventional public transportation system, the calculation method of the characteristics of the conventional public transportation system is established by using the database and the geographic information system software, and the data in Chengdu is used to calculate the examples.Thirdly, the relationships between the layout index of the modified road network and the density of the bus network, the degree of the center of the datum and the mileage of the bus lines and the turnover of the passenger flow are studied by means of regression analysis.The results show that the fitting degree among the three pairs of indicators’ degrees are 0.54,0.87 and 0.84 respectively, which means, there is a strong positive correlation among the three pairs of indicators. In other words, the density of the road network which can be effectively used by trafficability and the attractiveness of regional land use are higher, and the region’s bus network density is also higher; moreover, the importance of the road in the network structure is higher, and the total mileage of the bus lines on it and bus passenger turnover are also higher.Finally, the research results of this paper are summarized, and the future research direction is also discussed.