Soon, you will get vehicle CNG even outside the networked cities.
In the near future, hopefully, if you travel outside cities like Delhi and Mumbai in a CNG vehicle, you may not need to bother about switching to costlier petrol if the fuel runs out.
The Petroleum and Natural Gas Regulatory Board, the country
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/go-green-even-when-touring-outside-your-city
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/business-standard-new-delhi
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/renewable-energy
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/energy
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/ludhiana-d
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/vadodara-d
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/india
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/cng
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/petrochemical-industry
[10] http://admin.indiaenvironmentportal.org.in/category/thesaurus/industry
[11] http://admin.indiaenvironmentportal.org.in/category/thesaurus/jamnagar-d