Characterizing China's road network development from a spatial entropy perspective

Understanding the spatial characteristics of road networks is crucial for the planning of road networks. Although road networks have been frequently evaluated in combination with various socioeconomic factors, the current road network development in developing countries still needs to be better understood. Combining road network density and spatial entropy for 2728 counties in China, we provide a comprehensive assessment of road networks and their key influencing factors. Our results indicate a significant spatial heterogeneity of the road network development, especially on both sides of the Heihe-Tengchong line. Demographic-economic and topographic variables jointly explained 54.2% and 65.1% of the spatial variations in road network density and entropy, respectively. Road entropy increases with road network density in line with a saturation curve from provincial to national scales, which offers guidance for future road planning. Using a K-means clustering analysis, we categorized China's road networks into four groups corresponding to the development stages. Our findings improve the current understanding of road network development in China and provide important implications for national road network planning in the future.