Sustainable urban transportation: impact of CO[sub2] mitigation strategies on local pollutants.

This paper assesses CO[sub2] mitigation strategies in Delhi and Mumbai against the dynamics of local pollutants. After testing against techno-economic feasibility, compressed natural gas (CNG) technology, four-stroke two-wheelers and battery-operated vehicles (BOV) were selected as candidate options for Mumbai and Delhi. Multiple constrained optimization for finding out the optimal mix of vehicles to meet the travel demand under the business-as-usual scenario for the period of 1998-2020 revealed the dominance of CNG vehicles. CO[sub 2] mitigation targets of 5, 10, 15, 20, 25% resulted in reduced stock of diesel and petrol vehicles, with the reduction spanning over different points of the above time period. In the case of Mumbai, battery-operated three-wheelers dominated the vehicular mix, with the share of CNG vehicles remaining at a standard level. CO[sub2] reduction targets did not influence the CNG option significantly. CO[sub2] mitigation influenced the dynamics of local pollutants considerably in both Delhi and Mumbai. In Delhi, TSP and SO[subx] reduction levels against the CO[sub2] mitigation target were found to be significant. In Mumbai, the percentage reduction in local pollution (TSP in particular) was higher than the target CO[sub2] reduction. Local pollutants other than TSP and SO[subx] showed an increasing trend against the CO[sub2] mitigation strategies in Delhi. In the case of Mumbai, all non-target pollutants showed a falling trend against the CO[sub2] mitigation strategies, though insignificantly for pollutants other than TSP and SO[subx]. [ABSTRACT FROM AUTHOR]