Chennai Metro Rail Limited (CMRL) has officially commenced the expansion of the city’s metro network under Phase II, following the successful implementation of Phase I and its extension since June 2015. With rising ridership across Corridors 1 and 2, the new phase aims to enhance connectivity and ease urban commuting.

Phase II spans a total of 118.9 km across three corridors, backed by funding from multiple international agencies, including the Asian Development Bank, Japan International Cooperation Agency, New Development Bank, and the Asian Infrastructure Investment Bank.

As part of the expansion, work has begun on Corridor 5, which extends 47 km from Madhavaram Milk Colony to Shollinganallur, passing through key hubs like Koyambedu, Porur, and Alandur. The corridor features five underground stations and 39 elevated stations.

To execute the underground tunneling for Corridor 5, four tunnel boring machines (TBMs) have been deployed, each named after distinct Tamil landscapes: Kurinji, Mullai, Marutham, and Neithal.