Abstract

The analysis of exhaust emission characteristics of in-use CNG vehicles has revealed a high percentage of compliance to the existing norms of exhaust emissions for motor vehicles. The present study stresses the need for notification of separate and more stringent norms for pollution under control certification for different category of CNG vehicles.

At present, only a small fraction of the total vehicles are operating on CNG. There is no doubt that CNG is a cleaner and comparatively environment friendly fuels as far as CO, HC and CO2 emission are concerned. But with the present number of CNG vehicles significant improvement in air quality is not envisaged unless suitable measures are taken to target the private vehicles in Dhaka. Also at this juncture it is not clear what strategy will be best suited in addressing the core issue of vehicular pollution and what price would be paid for reducing the vehicular air pollution load in Dhaka? However, there appears to be no clear road to attain air quality improvement under present circumstances.