Tunnelling operations have commenced on the Greenways Road-Mandaveli stretch under Corridor III (Madhavaram Milk Colony SIPCOT) of the Chennai Metro Rail Project Phase II. The project involves the development of three metro corridors (Corridors III, IV and V) totalling 118.9 km in Chennai, Tamil Nadu. The majority of the project is underground, with only a few short stretches elevated. It includes a total of 128 stations. The work on Corridors I and II has been completed under Chennai Metro Phase I.