Pollution Due to Trucks - Gross Polluters in Bangkok

As part of the DIESEL program (Developing Integrated Environmental Strategies for Evaluating Land Transport) in Bangkok, a series of surveys were conducted to understand the driver behaviour and driving cycles for the heavy duty vehicles (HDV) and the light duty vehicles (LDV). Following the surveys, approximately 250 vehicles, including a mix of manufacturers, age, and fuel quality, were tested for emission rates for the primary pollutants.



This study was supported and funded mutiple agencies and primarily lead by a teams from the Pollution Control Board in Bangkok and the World Bank in Washington DC, USA. The final report was dessiminated along with summary of emission factors at a workshop in June 2008 in Bangkok.

The emission tests emphasized the importance of going after the gross polluters in the fleet for effective management of the emissions in Bangkok. The three tables below presents an analysis of the emission tests for the three categories light duty vehicles, buses, and trucks. The total emissions (in gm) presented for each of the category represent the sum of all the emission factors measured and used here to estimate the fraction of the gross polluters among the fleet.




For example, for the light duty vehicles, the 24 percent of the vehicles are (9 out of 38) are polluting the most contributing approximately 46 percent of the emissions. A direct abolishment of the gross emitters will result in a faster reduction of fleet emissions.

Similarly, for the buses and trucks, where the average fleet age is high, the percentage of vehicles polluting the most is high. Among the heavy duty trucks, 15 percent of the fleet contributes to approximately 45 percent of the emissions. It is important to note that this is based on the sample used for the emissions testing, which was assumed representative of the ~3.9 million vehicles on road in Bangkok.

The analysis provided a basis for strategy development for in-use old and incoming new vehicles, which is detailed in the DIESEL final report.

Also see

• Pollution from trucks in Delhi
• Pollution from trucks - Dhaka & Kolkata
• Average vehicular emission factor databases