Due to regulations and compliance issues for urban centers
Links:
[1] http://admin.indiaenvironmentportal.org.in/reports-documents/co-benefits-management-options-local-pollution-ghg-emissions-control
[2] http://admin.indiaenvironmentportal.org.in/category/author/sarath-guttikunda
[3] http://admin.indiaenvironmentportal.org.in/category/publisher/simple-interactive-models-better-air-quality
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/air-pollution
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/urban-air-quality
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/carbon-dioxide
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/cng
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/climate-change
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/green-house-gases
[10] http://admin.indiaenvironmentportal.org.in/category/thesaurus/road-transport
[11] http://admin.indiaenvironmentportal.org.in/category/thesaurus/high-capacity-bus
[12] http://admin.indiaenvironmentportal.org.in/category/thesaurus/congestion-pricing
[13] http://admin.indiaenvironmentportal.org.in/category/thesaurus/asia
[14] http://admin.indiaenvironmentportal.org.in/category/thesaurus/india
[15] http://admin.indiaenvironmentportal.org.in/category/thesaurus/global