November 04, 2025: Mumbai’s transport infrastructure is set for another major leap, with the Mumbai Metropolitan Region Development Authority (MMRDA) proposing a vast 70-km underground tunnel network aimed at easing surface-level congestion across the city, according to a report by The Print.
The project will be executed in three phases, with MMRDA currently in the process of appointing a consultant to prepare a techno-economic feasibility study and a detailed project report (DPR) for Phase One. “The tunnels will help divert a significant amount of through traffic underground and reduce the surface-level congestion. The idea is to help ease bottlenecks across the city’s arterial routes,” a senior MMRDA official was quoted as saying in the report.
Phase One: Coastal Road to BKC and Airport
The initial 16-km phase will connect the southern end of the coastal road—from Marine Drive and the Worli end of the Bandra-Worli Sea Link—to the Bandra Kurla Complex (BKC) and Terminal 2 of the Chhatrapati Shivaji Maharaj International Airport. It will also link to the upcoming Mumbai-Ahmedabad bullet train station at BKC, boosting multimodal transport integration.
Future Phases: Expanding Citywide Connectivity
The second phase, spanning about 10 km, will establish an east-west corridor between the Eastern and Western Express Highways, offering direct airport access and smoother cross-city travel. The third and final phase—approximately 44 km long—will create a continuous north-south underground route, streamlining passenger and freight movement without adding pressure to city roads.
Integrating with Ongoing Mega Projects
This ambitious network will complement ongoing tunnel projects, including the 9-km Orange Gate–Marine Drive tunnel connecting the Eastern Freeway to the coastal road (expected by 2028–29) and the 11.85-km Thane–Borivali twin tunnel under Sanjay Gandhi National Park, slated for completion by 2028.
