 The Metro uses rolling stock of two different gauges . Phase I lines use 1 @,@ 676 mm ( 5 @.@ 499 ft ) broad gauge rolling stock , while three Phase II lines use 1 @,@ 435 mm ( 4 @.@ 708 ft ) standard gauge rolling stock . Trains are maintained at seven depots at Khyber Pass and Sultanpur for the Yellow Line , Mundka for the Green Line , Najafgarh and Yamuna Bank for the Blue Line , Shastri Park for the Red Line , and Sarita Vihar for the Violet Line . Maglev trains were initially considered for some lines of Phase 3 , but DMRC decided to continue with conventional rail in August 2012 . 
