In the wake of heavy footfall in the Metro trains, the DMRC will soon attach extra coaches to some of its trains to increase their carrying capacity.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/metro-capacity-increase
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/asian-age-new-delhi
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/public-transport
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/urban-transport
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/metro
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/delhi-metro-rail-corporation-dmrc
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/delhi