Abstract
It is important towards low carbon society to figure out CO2 emissions from every transportation mode. This study estimates life cycle CO2 (LC-CO2) emissions from urban passenger transport modes; bicycle, light rail transit (LRT), bus rapid transit (BRT), taxi and city-center bus service. It clarifies how much introduction of alternative transport modes can reduce CO2 emissions. Evaluation includes vehicles, infrastructures of each modes and impacts on to existing transport modes. New infrastructure construction may reduce existing traffic lanes, attract congestion, and change fuel consumption. This system boundary can include such mechanism.
As a result of this analysis, LC-CO2 per passenger km from bicycle is 80-90% lower than passenger car. Even if new cycling road or LRT rail track or BRT road is constructed on a part of existing road for passenger car, CO2 emissions are not always reduced. If passengers change transport mode from passenger car to bicycle, LRT or BRT, CO2 emissions increase by construction of new system. In order to reduce CO2 emissions, new transport mode introduced on a road which daily traffic volume is 20,000 passengers requires to achiave following condition; 1) if there are no electric cars, 23% of passenger cars change to new transport mode, 2) if electric cars become popular, 18% of passenger cars change to new transport mode.
