Prospects of inspection and maintenance of two-wheelers in India

Two-wheeler vehicles in Delhi, India-roughly 70% of the total vehicle fleet -are responsible for a significant portion of the city's vehicle emissions and petroleum consumption. An inspection and maintenance (I/M) program that ensures vehicle emission control systems are well maintained can complemen t other emission reduction strategies. This paper presents the initial find ings of extensive data collected on vehicle characteristics and emissions f or two-wheeler vehicles operating in Delhi in a series of I/M camps conduct ed by the Society of Indian Automobile Manufacturers and various partners i n late 1999. The analysis shows idle HC and CO emissions [measured in terms of parts per million (ppm) and volume % (vol %), respectively] in a slow declining tren d with subsequent model years, reflecting tighter emission standards and mo re advanced emission technologies. The I/M benefits-3 vol % and 39% reducti on in idle and mass CO, respectively; 40 vol % and 22% reduction in idle an d mass HC, respectively; and a 10-20% increase in fuel efficiency-were high er than those reported in the literature. Although these benefits are subst antial, any implementation strategy needs to consider cost-effectiveness. I n the present study, only 10% of vehicles-contributing 22% of the total veh icle emissions-failed the idle CO standard. Fleet emissions data variabilit y necessitates a large sample size to develop a baseline for the vehicle fl eet, but a smaller, scientifically designed sample and better data collecti on quality could periodically track the benefits at future camps.