The impact of traffic networks on urban sprawl: A case study for Hubei Province in central China

China has experienced a dramatic process of urbanization and urban sprawl with a rapid built-up land increasing. The spatial increasing trend of built-up land is determined by various factors, such as government policy, land use patterns, population growth, economic development, and traffic network. Since the impact of traffic network is distance related and various traffic networks make their own effects on urban sprawl, the effects of traffic network on urbanization are complex. Therefore, it is necessary to find out how different traffic networks impact the spatial process urban sprawl. Hubei Province in central China is taken as a case study area. Six types of traffic networks are considered, including highway, mass transit special line, rail, country road, state road and nation road. Land use maps of Hubei province from 1990 to 2010 are retrieved from data center of Institute of geographic sciences and nature resources. The correlation between network density and a total area of built-up land in each administrative unit is analyzed. Then, the distance map of each traffic network is obtained. Last, the area of built-up land of 1990 to 2010 at different distances from each type of traffic network is calculated and analyzed. According to the results, it is found that larger area of built-up land occurs along with higher traffic network density (with r square as 0.6253), and different networks have various influencing distance on built-up increasing. Specifically, the influencing distance of a highway is about 17000m, of a mass transition special line, is about 50000m, of a rail line is about 35000m, of a country road is about 5000m, of a state road is about 95000m, and of a national road is about 20000m. It is concluded that the traffic network does affect the spatial process of urban sprawl, and this influence changes along with the type of traffic network, the distance from the network, and the density of the network.