How road network transformation may be associated with reduced carbon emissions: An exploratory analysis of 19 major Chinese cities

Abstract

The number of automobiles and traffic carbon emissions continues to increase. Reducing traffic energy consumption and carbon emissions in urban settings is essential in urban science and environmental research. Previous studies have demonstrated that traffic carbon emissions are related to road network form. However, the relationship between road network form and traffic carbon emissions has not been established, and traffic carbon emissions reduction by the transformation of road network form is still uncalculated. To fill these gaps, we clustered road network forms based on 11 morphological measurements, examined the relationship between road network forms, vehicle ownership, and carbon emissions, and estimated the traffic carbon emissions lowered by transforming road network forms. Our analysis shows 1) Road network sprawl is not linearly related to car ownership; 2) There are significant differences between the carbon emissions of different road network forms; 3) Road network form transformation can reduce annual traffic carbon emissions by 1.13 to 14.35 %. This study assesses the possible carbon reduction from road network form changes, which has direct planning consequences. The study methods and ideas are easily transferrable to different spatial contexts, providing a paradigm for global transportation emission reduction planning and execution.