The project spans approximately 10 km, including 7 km of underground twin tunnels, and aims to connect the Eastern Freeway with the Coastal Road and Marine Drive. Once operational, the tunnel is expected to reduce travel time between Orange Gate and Marine Drive from the current 22–40 minutes to around 5–7 minutes.
The twin tunnels will each have two traffic lanes, measuring 3.2 metres wide, along with an emergency lane. Cross passages connecting the tunnels are planned at intervals of 300 metres to facilitate emergency access.
The underground route will pass beneath Metro Line 3 and railway lines at depths ranging from 12 to 52 metres. It will also run beneath areas containing around 700 residential buildings and heritage precincts, requiring construction at varying underground depths.
According to the project update, 526 tunnel lining rings have been installed as part of the excavation work. The official completion deadline is December 2028, while the project is targeted for completion by June 2028.
Once completed, the tunnel is expected to improve connectivity between eastern and western road corridors in South Mumbai and reduce travel time for commuters using the route.
