Variability in Emission Rate of Auto-Rickshaw Based on Real World Driving Profile: A Case Study in Guwahati City

Auto-rickshaw is an important para-transit mode of urban transportation in India. Cheap in fair but old technology and adulterated fuel quality make it emission intensive. Therefore, this study is aiming the emission assessment of most demanding mode of transportation. The study investigated the variation in the emission rate with respect to operating kinetics by real-world on-road emission measurements of driving profile. The video clips screening revealed that owing to smaller size auto-rickshaw negotiates the traffic, smaller streets and weaves through the mixed traffic which increases frequency of wear and tear engine and increases the emission rate. During peak hours up to 80% of time auto-rickshaw operates in speed 6–28 km/h and acceleration -1 to $1\mathrm {m}/ \mathrm {s}^{2}$, which subjected to higher frequency of stop-and–go pattern of traffic flow and therefore causing higher engine load, subjected to higher emission rate. Each pollutant showed different behavior for the same variations in speed and acceleration. The emission rates of CO and HC was found higher at speed range12–30 km/h whereas emission rate of NOx and CO2 were found higher speed range of 30–40 km/h. The evaluation of travelling behavior corresponding instantaneous emission of auto-rickshaw concludes that and the improving vehicle flow and reducing frequency of sudden acceleration and deceleration could curb emission rate and reduce fuel consumption.