EFFECT OF SPEED ON EMISSIONS OF AIR POLLUTANTS IN URBAN ENVIRONMENT: CASE STUDY OF TRUCK EMISSIONS

Abstract

Dynamic emission factors and emission inventories of CO, VOC, VOCevap., NOx, SOx and PM
of truck in Bangkok, Thailand were developed using IVE (International vehicle emission) model for the year
2012 to 2024. The year 2012 was chosen as base year since fuel quality had been improved from Euro II to
Euro IV standard from that year. Speed of truck driven in study area was chosen as variable parameter for
sensitivity analysis of its influence to the emissions of air pollutants because there are no further plans in
upgrading or improvement of fuel quality during this period. Truck’s Bangkok driving cycle was used as
input data in the IVE model. Average speeds used in the model simulation were varied from existing
condition (15 km/hr) to the maximum of 80 km/hr. It was found that an average speed of 40 km/hr was the
optimal speed in reducing of air pollutants emitted from truck. At this speed, reduction of emission factors of
air pollutants as compared with current average velocity of 15 km/hr were about 46%, 54%, 16%, 51%, 53%
and 27% for CO, VOC, VOCevap., NOx, SOx and PM, respectively. Therefore, efforts in increasing average
speed of at least to about 40 km/hr can be used as a measure to achieve the sustainable transport particularly
in the green logistic businesses.