Effect of transit-oriented development on air quality in neighbourhoods of Delhi

Air quality index remains an area of concern for India at the national level, provincial (state level) and the municipal level (urban areas). The Indian government is using transit-oriented development TOD based urban design to reduce private vehicle usage [40]. However, there are few studies that explore the nature of the built environment that needs to be developed in line with TOD principles. This study uses two methodologies: the land use regression analysis and the TOD index analysis to ascertain the nature of the built environment in line with TOD policies in the context of New Delhi. Land use regression analysis makes use of urban form indicators for the study neighbourhoods in New Delhi as independent variables. The relationship between these urban form variables and the air quality index is tested. The second methodology creates a composite index by amalgamating the built environment indicators into a single index using the information entropy weighting method. This index proves useful in measuring the "TOD-ness" of the neighbourhoods of New Delhi to ascertain the relationship of TOD with air quality. The results from the study serve as inputs to urban and transport planners. Future urban and regional plans can be developed in line with the results of this study.