Transit vehicles, which use Delhi roads but have no business in Delhi, pose a serious management challenge. Transit vehicles pose a serious problem, as there is a wide divergence between the emission regulations enforced in Delhi and outside the city. While Delhi adheres to Euro II standards, cities neighbouring Delhi mostly adhere to Euro I standards. Thus the transit vehicle, which uses Delhi, contributes considerably to the pollution load in the city. These transit trucks thus negate whatever gains Delhi is making as a result of cleaner fuels.
Links:
[1] http://admin.indiaenvironmentportal.org.in/reports-documents/special-report-non-destined-transit-trucks-using-delhi
[2] http://admin.indiaenvironmentportal.org.in/category/publisher/environment-pollution-prevention-control-authority
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/environment-pollution-control-authority-epca
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/heavy-duty-vehicle
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/transport
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/supreme-court
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/delhi