Estimation of CO2 and CO emissions from auto-rickshaws in Indian heterogeneous traffic

In this study, the emission factors of CO2 and CO for diesel auto-rickshaws were quantified on rural and urban roads in Sangareddy district of Telangana state, India, under real-world driving conditions. The measured emission rates were observed to be influenced by road type, speed, and acceleration. The CO2 and CO emission rates were higher at a speed range of 35–45 kmph, compared to a speed range of 5–10 kmph and 15–30 kmph. The average emission factors of CO2 and CO on urban roads were found to be 1.69 and 1.89 times higher than rural roads, respectively. The developed emission factors of CO were found to be approximately 10 times higher than that prescribed by both Bharat Stage III (BS III) and Bharat Stage VI (BS IV) emission standards. Insights from this study will help in understanding real-world emissions of diesel auto-rickshaws in urban and rural traffic and will act as a reference for policymakers to develop emission baselines.