ANALYZING THE EFFECT OF VEHICULAR VARIABLES ON TAILPIPE EMISSIONS FROM TWO- WHEELERS

Abstract

Countries with huge population and inefficient public transportation systems have resorted to the use of two wheelers to combat congestion, survive economic pressures and reduce traffic accidents. This includes Asian nations like India and Indonesia. African countries like Nigeria and Ghana prefer motorcycle use due to inability to afford cars, as result of high unemployment rate. In India, two wheelers account for about 70 percent of the overall vehicular fleet. It, therefore, makes it of paramount importance to explore the key vehicular variables affecting emission from two-wheelers. From the tailpipe emission testing of 272 two-wheeled vehicles (motorcycles and scooters), we managed to get a clear comprehension of the effects of vehicular independent variables on the emission parameters. Following the data analysis, it is evident that the vehicular variables, such as mileage, age, and complying emissions standards, have a very strong influence on the tailpipe parameters CO and HC (carbon monoxide and hydrocarbon). Motorcycle and scooters’ age and mileage were both significantly correlated with CO and HC (For age, R2 = 0.846 and 0.815, respectively, and for mileage, R2 = 0. 841 and 0.809 respectively). As regards to the engine-specific independent variables, the fuel ignition system played a significant role in CO and HC emissions, as it was discovered that more recent and sophisticated versions of two-wheeler engines had lower maximum emissions values when compared to older versions. Also, kerb weight has a poor correlation to HC and CO emissions (R2 < 0.3), implying that approximately 30 percent of vehicles with the same kerb weight had the same CO and HC emissions. The logarithmic emission equations generated in the present study can reliably predict CO and HC emission levels rooted on vehicular traits. It is recommended to upgrade the phasing-out policy basis of such traits. For future studies, multivariate correlation of emissions on engine and vehicle specific parameters can be carried out, to access the level of combined impact.