Research On The Atmospheric Environmental Traffic Capacity For Highway

The highway atmospheric environmental traffic capacity refers to that within a region onthe highway, in a certain road and traffic condition and air environmental quality standard, themaximum number of motor vehicles can be adopted in the unit of time. With the rapiddevelopment of China’s economy and society, the number of motor vehicles and the demand forhighway transportation increase rapidly, resulting in the increasing deterioration of highwayatmospheric environment. The transport system has become a major source of pollution of thehighway atmospheric environment. Therefore, the research of the highway atmosphericenvironmental traffic capacity can provide a scientific basis for the calculation of the totalamount of highway air pollutants, the design of road construction projects, the management ofhighway operations and the control of environmental pollution, which has important practicalsignificance.This article is based on the sustainable development of the highway transportation system,analyzing the factors that influence the plain highway atmospheric environmental traffic capacity,adopting the hourly average second standard concentration of national air quality as a value oftraffic emissions in the plain highway atmospheric environment. And evolving the parametersthat the model requires and using the associated methods of on-site monitor, numericalsimulation and model establishment, this essay establishes the model of plain highwayatmospheric environmental traffic capacity and makes a case study. The conclusions are asfollows:（1）The evaluation factors of highway atmospheric pollution are identified by analyzingthe air quality standards and the formation mechanism of the motor-vehicle emission. Given thetypes of the vehicles in China, a calculation method of the emission source in the highway is putup based on the model of MOBILE6.2.（2）Through a comparative analysis between the HIWAY series and CALINE series ofpollutant dilution model of the typical line source, a dilution factor model of the highwaypollutant is raised based on the CALINE-4dilution model.（3）Based on the constraints analysis of the highway atmospheric environmental traffic capacity, using the theory of traffic flow and vehicle emissions and the vehicle pollutants asevaluation factor, the calculation model of the highway atmospheric environmental trafficcapacity is deduced. Hour traffic calculated is the highway atmospheric environmental trafficcapacity of pollutant and the highway atmospheric environmental traffic capacity takes theminimum value.（4）Using the CO as evaluation factor, according to the actual data of meteorology,pollutants and traffic which are continuously monitored and adopting the method proposed inthis paper, the case study calculates the plain highway atmospheric environmental trafficcapacity of studied peak periods (13:00to17:00) are respectively1393PCU/h,1662PCU/h,1578PCU/h,1497PCU/h, then we can see the actual traffic volume has exceeded theenvironmental allowable value of second standard concentration of hourly average of national airquality.