The recognition of the contribution of vehicular emissions to atmospheric pollution has led to much research and inventory build up particularly in industrialised countries. Consequently, emissions data for use in planning analysis is readily available there, but in the vast majority of developing countries, Kenya included, this is not the case. It is generally accepted that due to a variety of factors, the emissions rates for vehicle fleets in developing countries are higher than those of similar vehicles in developed countries. These factors include poorer maintenance conditions, the longer service life and the amount of load the vehicles have to carry. However, there is hardly any prior research aimed at trying to cost effectively estimate the actual emission parameters in these countries. This paper proposes a new approach that has been developed and applied to estimate emission coefficients for CO, HC and NOx in Kenya. The main premise of this approach is to acceptably estimate adjustment factors with which emissions coefficients from industrialised countries can be modified to suit the vehicle fleet in a particular developing country. Emissions coefficients for Kenyan vehicles were estimated to be up to two to three times higher than typical values in industrialised countries.
Abstract