Urban Road Network Expansion and Its Driving Variables: A Case Study of Nanjing City.

Ge Shi,Peng Ye,Yang Li,Liang Ding,Nan Jiang,Jie Shan

doi:10.3390/ijerph16132318

Abstract

Developing countries such as China are undergoing rapid urban expansion and land use change. Urban expansion regulation has been a significant research topic recently, especially in Eastern China, with a high urbanization level. Among others, roads are an important spatial determinant of urban expansion and have significant influences on human activities, the environment, and socioeconomic development. Understanding the urban road network expansion pattern and its corresponding social and environmental effects is a reasonable way to optimize comprehensive urban planning and keep the city sustainable. This paper analyzes the spatiotemporal dynamics of urban road growth and uses spatial statistic models to describe its spatial patterns in rapid developing cities through a case study of Nanjing, China. A kernel density estimation model is used to describe the spatiotemporal distribution patterns of the road network. A geographically weighted regression (GWR) is applied to generate the social and environmental variance influenced by the urban road network expansion. The results reveal that the distribution of the road network shows a morphological character of two horizontal and one vertical concentration lines. From 2012 to 2016, the density of the urban road network increased significantly and developed some obvious focus centers. The development of the urban road network had a strong correlation with socioeconomic and environmental factors, which however, influenced it at different degrees in different districts. This study enhances the understanding of the effects of socio-economic and environmental factors on urban road network expansion, a significant indicator of urban expansion, in different circumstances. The study will provide useful understanding and knowledge to planning departments and other decision makers to maintain sustainable development.

Highlights

Rapid urban expansion is an important period for developing countries due to the burgeoning economy as well as the road network expansion [1]
As we discovered in this study, previous studies have shown a lot about the correlations between road network expansion and human–land related elements, they differ in different districts
This study considered the GDP of first second and third industries, PM2.5 concentration level, and population as the most affected elements of urban road network expansion, as the parameters entered into the geographically weighted regression (GWR) model

Summary

Introduction

Rapid urban expansion is an important period for developing countries due to the burgeoning economy as well as the road network expansion [1]. The world’s urbanization rate has increased from. 39% to 52% for the last three decades and is expected to reach around 66% by the year 2050. The increase in urbanization in developing countries is much more rapid than in developed countries [2,3]. Res. Public Health 2019, 16, 2318; doi:10.3390/ijerph16132318 www.mdpi.com/journal/ijerph

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