Optimal modal transport choice in the face of different strategies for air quality management in urban transportation planning

The recent economic expansion along with the population growth experienced in developing countries has had a big impact on the development of large cities like Delhi, India and Beijing, China. Accompanied by Delhi's rapid spatial growth over the last 25 years, urban sprawl has been contributing to increased travel. The current land-use plan for 14 satellite cities surrounding Beijing would commit it to be an “automobile city” for many decades to come. The vehicle fleet projected at current growth rates will result in more than 13 million vehicles in Delhi and about 7 million vehicles in Beijing in 2020, a more than quadrupling of their current vehicle fleets. Planning and managing such rapidly growing transportation sectors will be a big challenge. Choices made now will have impacts lasting well into the middle of this century.; With such rapid transport growth rates, automobile emissions have become the fastest increasing source of urban air pollution. In India and China most urban areas, including Delhi and Beijing, already have major air pollution problems that could be greatly exacerbated if growth of the transport sector is managed unwisely. The transport plans designed to meet such large increases in travel demand will have to emphasize the movement of people not vehicles for a sustainable transportation system.; The spreadsheet simulation models developed to investigate future vehicular emissions from Delhi and Beijing's transportation sectors indicate that technical advancement in vehicle technologies and fuel qualities alone will not solve the air pollution problems faced by these cities and that land use planning and travel demand management measures directed at reducing traffic congestion will need to be employed in cooperation.; The mathematical model developed for Delhi estimates the optimal transportation mix to meet the projected passenger km demand, while satisfying environmental goals, reducing congestion levels, improving system and fuel efficiencies through exploiting a variety of policy options at the minimum overall cost or maximum welfare from transport. The results suggest that buses will continue to satisfy most of passenger transport in Delhi in the coming decades, so planning done in accordance with improving the operation of buses is crucial.