Assessment of urban passenger fleet emissions to quantify climate and air quality co-benefits resulting from potential interventions

Lack of robust data to assess the effects of different policies may hamper the design and implementation of effective solutions to reduce traffic emissions. This study analyzed the emissions of passenger fleets in Bandung, Indonesia, illustrated with three emission scenarios against the 2015 baseline. Local surveys were conducted to get traffic activity data for International Vehicle Emissions (IVE) modeling to generate emission factors (EFs) relevant to actual fleets and driving conditions in the city. EFs obtained for gasoline fleets that could have been affected by the leaded gasoline used prior 2006 were adjusted for the catalyst deactivation effect. Annual emissions (Gg/year) for CO, VOC, NOx, PM, BC, OC, NH_3, air toxics and SO₂ were 168, 36, 16, 1.8, 0.68, 0.72, 0.68, 4.7 and 0.42, respectively. Emissions of CO₂, N₂O and CH₄ were 2679; 0.07 and 5.8 Gg/year, respectively. Collectively, the 20-year global warming potential (GWP) of the emissions was 6770 Gg/year CO₂ eq. Analysis of potential interventions of technology intrusion of Euro3 (S1) and Euro4 (S2), and catalyst revamping (S3) showed potential co-benefits to air quality improvement and climate forcing mitigation. S1 would reduce the toxic pollutants emissions by 62% and GWP by 29%; corresponding reductions would be 68% and 45% for S2 and 47% and 16% for S3. Actual measurements are required to validate the potential emission reductions by catalyst revamping.