Life cycle emissions from a bus rapid transit system and comparison with other modes of passenger transportation

This work presents Life Cycle Emissions from the Bus Rapid Transit System (BRT) TransMilenio compared to other modes of passenger transportation in Bogota, Colombia (R). We applied the life-cycle assessment (LCA) and the well-to-wheels approach. We used the OpenLCA software, the Ecoinvent database and all the information available in the city to perform this LCA. The impact category climate change (CO2-eq) and emissions of PM2.5, CO and NOx were considered. The functional unit is mass of pollutant per kilometer and per passenger transported (mass/km-passenger). Results of this work indicate that public transport buses including BRT produce the lowest emissions of CO2-eq, CO and NOx. While the lowest emissions of PM2.5 were achieved by an electric BRT and buses powered by natural gas. The highest emissions of PM2.5 are given by motorcycles and private cars, and taxis present the highest emissions of NOx. Finally, if TransMilenio buses change from diesel to electricity, CO2-eq and PM2.5 emissions would be reduced by 86% and 88%, respectively. However, these values are lowerthan reductions achieved when strategies are focused on controlling emissions from other vehicle categories.