STUDY OF EFFECT OF SPEED, ACCELERATION AND DECELERATION OF SMALL PETROL CAR ON ITS TAIL PIPE EMISSION

Abstract

Pollution from vehicles is due to discharges like Carbon monoxide (CO), Carbon dioxide (CO2 ), Hydrocarbon (HC) and Oxides of Nitrogen (NOx) through their tailpipe. Cars, being in dominant proportions (36.5%) in Indian traffic stream with small cars above 50% in total car proportions, are the main contributors to pollutants. Literature reveals that all factors being constant, at signalized intersection, car emission rates are the function of speed and acceleration. Since it is difficult to collect speed and position data at the actual intersection, this study is conducted on link road between National Highway 31 and IIT Guwahati, India, replicating the queue leader at signalized intersection. Tailpipe emissions are measured using onboard emission measurement system and speed and position data are measured using GPS device. Study illustrates that tailpipe emissions like CO, HC and NOx are sensitive to vehicle speed at similar acceleration level. Tailpipe emission rate initially decreases with increase in speed and then increase afterwards with further increase in speed, at similar acceleration level. Emission rates are found to increase with increase in vehicle acceleration rate. It was observed that deceleration does not influence tailpipe emission of small cars.