Traffic characteristics and pollutant emission from road transport in urban area

Abstract

In this work, the traffic characteristics and emissions of air pollutants were predicted for two vehicle classifications (passenger cars and trucks) at the national highway in Kyoto City, Japan. Traffic characteristic information (traffic volume, travel speed, and degree of congestion) was estimated based on the digitised data collected by the Ministry of Land, Infrastructure, Transport, and Tourism (MLIT) of Japan. A vehicle emission model, known as the computer program to calculate emissions from road transport (COPERT), was utilised to compute the emission factors (EFs) and total emissions of air pollutants in terms of exhaust particulate matter (PMExh), benzene (C6H6), carbon monoxide (CO), and nitrogen oxide (NOx). Input variables, such as fuel data, activity data, driving conditions, and meteorological conditions, are needed. The findings revealed that the pollutant emissions reached the higher values over the slower travel speed phase. Road no. 1 with the most congested road segment has intensified vehicle numbers, and the slowest traffic flow movement exposed a greater magnitude of pollutant emissions. C6H6 and CO emissions are obviously more emitted from the passenger cars whereas the trucks are responsible for the greater emission of NOx and PMExh. The EFs of pollutants were compared with the Japanese Emission Standards through JE05 and JC08 chassis dynamometer test cycles. The estimated EFs showed inconsistency with the EFs derived from the test cycles. These results may be deployed as the input in air quality dispersion modelling in urban areas for designing the air pollution abatement strategy.