Towards sustainable passenger transport: Carbon emission reduction scenarios for a medium-sized city

Abstract

The sustainability of transportation systems is frequently linked to human preferences, hence it is pertinent to align quotidian commuting choices with sustainable development goals. The main goal of the present research was to simulate eight scenarios designed to reduce the carbon dioxide emissions of passenger transport in a Colombian medium-sized city, taking into account the Global Warming Potential (GWP) of public and private vehicles, obtained by means of Life-Cycle Assessment (LCA). In this work we compared the environmental efficiency of the scenarios in order to make a contribution to the scientific discussion on sustainable mobility policies. Measures such as reducing the number of the most polluting vehicles, optimising the modal shares of public and private transportation systems, integrating electric vehicles, increasing the use of bicycles, and reducing mobility, have been tested. The results show that the current annual emissions from passenger transport in the selected city (263.98 kt CO2-eq) could be decreased by up to 64.28% by implementing a 50% reduction in individual Trips per Day (TpD) and distances travelled by private and public vehicles. In addition, increasing the public bus fleet by 50% could yield a 56.92% reduction in the carbon dioxide released, while using an average occupancy of 30 passengers in buses could decrease the total emissions by 25.73%. Augmenting the occupancy ratio of private vehicles was shown to yield a 22.71% reduction in carbon dioxide released. Also, increasing the electric vehicle fleets by 50% can produce carbon emission reductions of 17.96% for the current energy mix and 20.08% for a 100% renewable energy mix; while boosting the use of bicycles and increasing the diesel car fleet yielded reductions of 9.24% and 5.06%, respectively. This article concludes that managing mobility and restricting commuting could be the most sustainable measure for life-cycle carbon emission reduction.