Rethinking bus transit in a developing country of the Middle East

Abstract

This study investigates the potential reductions in energy use, greenhouse gas and pollutant emissions from natural gas, hybrid and battery electric buses compared to diesel bus in real driving conditions in Lebanon, a developing country of the Middle East with an unsustainable road transportation system. A Euro V compliant 12-meter bus is considered in the modelling, and appropriate real driving cycles are developed for four operating conditions including severe congestion, peak, off-peak and bus rapid transit operation. Results show that accounting for additional energy consumption from the use of climate control auxiliaries can significantly impact the performance of all bus technologies in this context, by 26.4% for compressed natural gas bus and up to 45% for parallel-hybrid electric bus. The energy consumption and environmental performance of all fuel bus technologies improve considerably in free-flowing traffic conditions, making bus rapid transit operation the most beneficial. Battery electric buses are found to be the best performers in all traffic conditions, conditional on having a clean energy supply at the power plants. Compressed natural gas buses do not provide significant GHG emission savings compared to diesel bus, but offer substantial reductions in the emission of harmful pollutants.