Analysis On The Impact Of Electronic Toll Collection Promotion On Traffic Emissions In Beijing

In order to ease traffic congestion on highways and reduce motor vehicle energy consumption and emissions,Ministry of Transport abolished provincial toll stations in2019,and replaced the existing toll collection system of Manual Toll Collection（MTC）and Electronic Toll Collection（ETC）with ETC as the main Toll system and MTC as the auxiliary one.At present,the analysis of the impact of ETC lanes setting is mostly from the perspective of traffic flow,travel speed and capacity,while the research from the perspective of motor vehicle emissions and the related studies on the impact of ETC lanes setting on emissions are few.Based on the study of vehicle emission model of MTC and ETC lanes,this paper establishes a quantitative method of vehicle emissions,and evaluates the promotion of ETC traffic policy in Beijing from the perspective of traffic environment,so as to provide theoretical basis for controlling and reducing vehicle emissions to the maximum extent.In order to achieve the above goals,this paper first preprocesses the working condition data of light vehicles collected by the on-board GPS devices in two toll lanes（MTC and ETC）,and preprocesses the emission data of light vehicles collected by the Portable Emission Measurement System（PEMS）.Then,based on the Vehicle Specific Power（VSP）emission measurement theory,the collected working condition data and emission data,the light vehicles’VSP distribution and VSP interval emission rates are respectively established.Secondly,this paper analyses the influence factors of emission rates and VSP distribution of MTC and ETC lanes.Focusing on VSP distribution under different average speed and different delay time,this paper found that according to delay time cluster VSP can reflect more driving characteristics of toll collection system vehicles than use average speed cluster VSP.There are differences in VSP distribution of upstream and downstream of MTC lanes,while the differences in VSP distribution of upstream and downstream of ETC lanes are not significant.And the differences in the basic emission factors of MTC and ETC lanes of light vehicles are compared.It is found that within the study area of toll stations（200m in the upstream and downstream）,the average emission reduction of CO₂,CO,HC and NOx are 36.4%,31.5%,38.2%and 30.7%respectively.Third,by using the length of the delay time to measure traffic demand,the M/G/K queuing model is used to calculate the delay time under different traffic demand.Through the delay time to realize the docking between the queuing model and the emission factor delay correction model.The delay correction model DCF-MTC for light vehicles on the MTC lanes under the influence of different delay times is established,and the delay correction model DCF-ETC for light vehicles on the ETC lanes under the influence of different delay times is also established.Finally,a calculation example is designed to evaluate the emission change of light vehicles after the cancellation of provincial toll stations in Beijing by combining the M/G/K queuing model and the delay correction model.Results show that when transform7 MTC lanes to ETC lanes,the traffic flow through ETC lanes changes from 20%to 95%,and the average total traffic demand of light vehicles of a toll station is 13195 pcu/d,within the study area of toll stations,is expected to reduce 618.33 tons of CO₂,1.31 tons of CO,0.18 tons of HC,0.05 tons of NOx of 8 provincial boundary toll stations in a year.The corresponding reduction ratio are 19.7%,21.0%,22.3%,16.0%,they will increase with the increase of traffic demand.