Influence of Road Patterns on PM_2.5 Concentrations and the Available Solutions: The Case of Beijing City, China

With the increase in urbanization and energy consumption, PM_2.5 has become a major pollutant. This paper investigates the impact of road patterns on PM_2.5 pollution in Beijing, focusing on two questions: Do road patterns significantly affect PM_2.5 concentrations? How do road patterns affect PM_2.5 concentrations? A land-use regression model (LUR model) is used to quantify the associations between PM_2.5 concentrations, and road patterns, land-use patterns, and population density. Then, in the condition of excluding other factors closely correlated to PM_2.5 concentrations, based on the results of the regression model, further research is conducted to explore the relationship between PM_2.5 concentrations and the types, densities, and layouts of road networks, through the controlling variables method. The results are as follows: (1) the regression coefficient of road patterns is significantly higher than the water area, population density, and transport facilities, indicating that road patterns have an obvious influence on PM_2.5 concentrations; (2) under the same traffic carrying capacity, the layout of “a tight network of streets and small blocks” is superior to that of “a sparse network of streets and big blocks”; (3) the grade proportion of urban roads impacts the road patterns’ rationality, and a high percentage of branch roads and secondary roads could decrease PM_2.5 concentrations. These findings could provide a reference for the improvement of the traffic structure and air quality of Beijing.