Urban Transport Scenarios in South Asia: Energy and Environmental Impact of Enhanced Public Transport Systems

Document Type

Journal Article

Publication Date


Subject Area

operations - traffic, planning - environmental impact, land use - impacts, ridership - forecasting, ridership - forecasting, policy - environment, policy - congestion, place - asia, place - urban, mode - mass transit


Urbanization, Transit, Traffic congestion, South Asia, Scenarios, Public transit, Projections, Mass transit, Local transit, Gridlock (Traffic), Fuel consumption, Forecasting, Environmental impacts, Environmental effects, Energy utilization, Energy consumption, Dhaka (Bangladesh), Colombo (Sri Lanka), Carbon dioxide, Bangalore (India), Automobile use, Automobile usage, Automobile travel, Air quality, Air pollution, Air pollutants


Motor vehicle ownership and utilization are growing rapidly in Asia, because of rapid urbanization and growing urban incomes. This sudden growth is resulting in increasing traffic congestion, fuel use, and CO2 emissions and in deteriorating air quality. This paper presents a common framework to explore scenarios of vehicle and energy use and emissions in three South Asian cities: Bangalore, India; Colombo, Sri Lanka; and Dhaka, Bangladesh. Scenarios are built by separately analyzing transportation activity (in tonne kilometers or passenger kilometers), modal structure (i.e., share of tonne kilometers or passenger kilometers occurring on each mode), modal energy intensity (in energy burned per tonne kilometer or passenger kilometer), and emission factors. Although the types of data available across cities vary widely and there are deficiencies and inconsistencies in the available data, the analysis suggests that motor vehicle use would roughly double in each city by 2020 in the business-as-usual scenario, largely because of expected income increases; fuel use and CO2 emissions would triple; and pollution loading would rise exponentially. An alternative scenario of slower vehicle and energy growth is explored, premised on substitution of personal vehicles with buses and reduction in traffic congestion. Consequently, fuel use and CO2 emissions would only double in Bangalore and Dhaka, whereas in Colombo the increase would not be significantly lower than in the business-as-usual scenario. The cumulative carbon mitigation potential over a 15-year period would be 13% in Bangalore, 9% in Dhaka, and 2% in Colombo. The drop in pollution loading would be different in each city.