Analysis Of Vehicle Emissions At Airport Terminal Curbside And Effects On Pedestrians Based On Microscopic Simulation

The rapid development of air transport industry has brought substantial increase of air passengers.This resulted in unprecedented pressure to the terminal curbside at the airport,causing such problems as traffic congestion,traffic chaos,and air pollution in surrounding areas.At the same time,since the airport terminal curbside is a gathering center of passengers,vehicle emissions will inevitably impose direct threat to the health of passengers.A fundamental requirement to solving the emission pollution problem at the terminal curbside is to accurately estimate emissions and their effects on pedestrians under various operational strategies and traffic conditions.Consequently,the research in this thesis aims to develop the model of analyzing the effect of vehicle emission on pedestrian at the terminal curbside of the airport.Since the emission is very sensitive to the operational characteristics of vehicles,the thesis also establishes a microscopic simulation model for emission estimations considering the complicated traffic conditions at the terminal curbside of the airport.The thesis applies the proposed models to the case studies at the Beijing Capital International Airport(BCIA).First,methods are developed for collecting the data at the airport terminal curbside,including basic static traffic characteristics data and dynamic vehicle and pedestrian data.As a result,the floating car trajectory data are collected by "circular" experiments.Thus,the standstill distance,dwell time,and travel time of vehicles and the travel time,luggage picking time,and the acceptable gap time of pedestrians are collected.Second,the model structure of emission estimation,pollutants distribution,and pedestrian exposure is developed and applied to analyze the effect of vehicle emission on pedestrian at the terminal curbside of the airport.an emission estimation model based on the simulation of the terminal curbside is established using the vehicle specific power(VSP).Then,the distribution of pollutants on the curbside area in front of the airport terminal is estimated by the dispersion model.Further,by analyzing the spatial and temporal distribution of the pollutant exposure to pedestrians,a pedestrian exposure model is developed for evaluating and analyzing the impacts of vehicle pollutants on pedestrians’ health.Third,a microscopic traffic simulation model for the airport terminal curbside is established for estimating vehicle emissions.Based the collected data,the stops of vehicles at the curbside and the weaving between vehicles and pedestrian are particularly analyzed,and key parameters for the simulation model are subsequently calibrated.After the calibration,the accuracy of the simulation model is improved and the simulation error of the travel time is all within 5%.In addition,the simulated and field collected VSP Bin distributions have shown a very similar pattern,meaning that the calibrated model can be applied to simulate the traffic operations at the airport terminal curbside and estimate vehicle emissions.Finally,the T3 terminal of the Capital International Airport is taken as the case study area to evaluate the optimized "3-minute-stop-restriction plan" using the proposed method of analyzing the effect of vehicle emission on pedestrian at the terminal curbside of the airport.The analysis shows that the travel time in the optimized "plan" has decreased by 27.4%compared with that in the existing plan.Moreover,the average delay is reduced by 9.8%.so the passage efficiency is effectively improved.The optimized effect is significant for the idling mode,e.g.the hourly pollutant emissions have decreased by 50.51%,and the emission factors of CO,NOx and HC are reduced by 4.51%,6.57%,and 15.02%respectively.Finally,the dispersion model is used to simulate the dispersion distributions of the three pollutants.Combined with the exposure time distribution of pedestrians at the curbside of the airport terminal,it is observed that the emissions of the pollutants are effectively reduced after the application of the optimized plan,thus,the total exposure has decreased significantly,and the pedestrian exposures and Inhaled Dose of CO,NOx.and HC are reduced by 4.47%,6.64%,and 16.37%.respectively.