Much of Phase 3 of Delhi Metro will be underground

The total length of the underground corridors in the proposed Phase-III will be almost equivalent to the total underground sections built so far by DMRC in Phase I and II.
"This makes construction of the Phase-III more challenging," a DMRC spokesman said.

Delhi Metro now has a total of 31 underground stations, while Phase 3 alone will have 28 underground stations.

"The total length of the underground corridor now is 48.06 kilometres and Phase 3 alone will have underground corridors of 41.044 kilometres," the spokesman said.

The decision to construct more underground corridors was taken this time to ensure that construction work causes minimum inconvenience to the people.

By constructing so many underground stretches, DMRC will also be able to avoid causing any damage to the existing infrastructure such as flyovers and roads, the spokesman said.
For the first time, three different tunneling stretches in Phase 3 will pass below existing underground Metro stretches in the city.

They are the underground stretch from Sarojini Nagar to INA on the Mukundpur–Yamuna Vihar corridor, Indira Gandhi Domestic Airport to Kalkaji on the Janak Puri West and Mandi House to ITO.