Research On The Influence And Mechanism Of Traffic Restriction Policy On Air Quality

With the rapid development of urbanization,the size of urban population and the number of motor vehicles are increasing rapidly.The limited road capacity cannot meet the growing travel needs of urban residents,which induces frequent urban traffic congestion.Traffic congestion has a serious negative impact on the urban environment and the lives of residents.How to solve the negative externalities caused by traffic congestion has both practical significance and academic value.This paper conducts an empirical analysis on the impact of motor vehicle restriction policy on air quality,and quantitatively identifies the impact of motor vehicle restriction policy on air quality.This provides a certain reference value for academic research and management practice in related fields.The existing literature has conducted a series of studies on the relationship between vehicle license plate restriction policies and air quality.However,these studies generally only focus on the effect of vehicle license plate restriction policy in one city,while ignoring the evaluation of the effect of vehicle license plate restriction policy in multiple cities.In addition,the research results of different literatures are also different,which is difficult to judge whether the implementation of policies is effective.Further,the vehicle license plate restriction policies implemented by cities are different.However,the research on the difference effect of this vehicle license plate restriction policy has rarely attracted the attention of scholars.In order to solve the above problems,this paper systematically explores the impact of vehicle license plate restriction policy on air quality in China based on the frontier research of existing literature.Specifically,this paper analyzes the impact of vehicle license plate restriction policies on air quality in several cities.According to the current vehicle license plate restriction policy,the classification is carried out to quantitatively measure the impact and heterogeneity of the implementation of vehicle license plate restriction policies in different regions and different combinations on air quality.By excluding other policies that may affect air quality,the effects of different combinations of vehicle license plate restriction policies are quantified.Furthermore,a congestion pricing model based on commuting comfort is designed to alleviate traffic congestion in the morning and evening peak hours.The main research contents of this paper are as follows:This paper analyzes the changes of air quality in 32 key cities in China from the perspective of vehicle license plate restriction policy.By using monthly panel data,a multi-period difference-in-difference model is constructed to evaluate the impact of vehicle license plate restriction policies on air quality in multiple cities.The results show that the implementation of the vehicle license plate restriction policy has significantly improved urban air quality.In contrast,the urban AQI index has improved after adding control variables,but it still has a positive effect on the improvement of urban air quality.Through the implementation of the vehicle license plate restriction policy,the improvement effect of the vehicle license plate restriction policy on the AQI index is further enhanced.This indicates that the mixed vehicle license plate restriction policy is better than the single vehicle license plate restriction policy.The types and quantities of the current vehicle license plate restriction policies in China are classified.Taking the Qinling-Huaihe River as the dividing line,Chinese cities are divided into northern and southern cities.Based on the daily panel data of cities,the influence of vehicle license plate restriction policy on air quality in southern and northern cities of China is analyzed by using the propensity score matching double difference model.It is found that the implementation of vehicle license plate restriction policy has improved the air quality in southern and northern cities of China.The effect of the vehicle license plate restriction policy weakens with the beginning of the heating season.After excluding holidays,the effect of the policy has increased significantly.However,the short-term and stricter license plate restriction policy in northern cities cannot improve urban air quality.Cities that implement the vehicle license plate restriction policy can also improve the air quality of surrounding cities that do not implement the restriction policy.Moreover,the study found that the effect of the vehicle license plate restriction policy does not increase with the superposition of the number of policies implemented.And the policy effect does not increase with the expansion of the restricted area.The vehicle license plate restriction policy does not directly improve air pollution,but improves air quality by influencing other related factors.This paper solves the endogenous problems that are common in the literature by using the difference-in-differences model.And the impact of vehicle license plate restriction policy on air quality and its transmission mechanism are systematically explored.After excluding other policies that may affect air quality,it is found that the implementation of motor vehicle license plate restriction policy has significantly improved urban air quality.The use of new energy vehicles can effectively reduce air pollution,but urban expansion cannot improve air quality.In general,the transmission mechanism of the motor vehicle license plate restriction policy is mainly through the restriction of private travel and the increase of urban greening.In addition,the transmission mechanism of different combinations of vehicle license plate restriction policies is also different.This means a comprehensive assessment when formulat ing relevant policies.Traffic congestion still occurs frequently in cities implementing vehicle license plate restriction policy.Given that different commuting modes give commuters different happiness,this paper attempts to quantify the comfort of commuting modes.Through the questionnaire survey,a congestion pricing model based on the relative comfort of commuting is constructed by using the disaggregate model as the tool model.In the optimization process,the carbon emissions caused by traffic congestion are calculated.Taking some areas of Xi ’an as the research object,the simulation results show that the selected road network speed and carbon emissions are optimal when the congestion pricing is 7 yuan.This paper evaluates the impact of motor vehicle restriction policies on air quality,which helps to assist cities or regions to improve urban traffic congestion and control urban air pollution.It provides theoretical analysis and data support for the urban transportation department to achieve the goal of carbon neutrality and carbon peak.