70-km tunnel linking Coastal Road, BKC bullet train station, Mumbai Airport: MMRDA begins work on DPR for project to reduce congestion

According to MMRDA officials, the tunnel system will span approximately 70 km and be constructed in three phases. An official said that it will connect key business and transport hubs, allowing motorists to bypass surface bottlenecks while linking directly to the coastal corridor and the high-speed rail network.

Phase I will be 16 km long and will stretch from the Worli Sea Link to BKC and the Airport, tying together the Coastal Road, the bullet train terminal, and the airport loop. This phase is expected to ease pressure on the WEH and SV Road.

Phase II of 10 km will be an east–west connector between the Eastern Express Highway (EEH) and WEH to shorten cross-city commutes.

Phase III will be the longest 44 km stretch and it will be a north–south corridor running the length of the city to serve both passenger and goods traffic.

The proposal to appoint a consultant for the project was cleared on September 30. The tender was issued on October 9, the pre-bid meeting took place on October 17, and bids will open on November 17.

Smoother, safer travel: Fadnavis

Chief Minister Devendra Fadnavis said the project would help Mumbai move faster and more efficiently.

“Mumbai’s progress depends on how quickly people and goods can move. The tunnel network will connect roads, the metro and the Coastal Road to create smoother, safer travel across the city,” he said.

Deputy Chief Minister and MMRDA Chairman Eknath Shinde called it a “new dimension of mobility”.

“This takes travel underground and adds a new layer to the city’s transport system. When integrated with the Coastal Road, the Metro and the Bullet Train, it will bring the idea of Mumbai in Minutes much closer,” he said.

Dr Sanjay Mukherjee, IAS, Metropolitan Commissioner, MMRDA, said the current stage is about understanding whether the project is technically and environmentally feasible.

“The DPR will examine ground conditions, the city’s traffic needs and environmental impact before moving ahead. If found viable, it will be built in stages,” he said.

The consultant will also study ventilation, safety and design aspects and assist MMRDA during future bidding. Officials said the underground routes would function like expressways, taking long-distance and through-traffic below ground and leaving surface roads freer for local movement and public spaces.

The tunnel network aligns with MMRDA’s broader plan to develop a network of underground corridors across Mumbai, connecting the Coastal Road, the Mumbai Trans-Harbour Link (MTHL), and other upcoming east–west connectors.

MMRDA is already working on two major tunnels, the Thane–Borivali twin tunnel (11.85 km, Rs 18,838 crore) and the Orange Gate–Marine Drive tunnel (9.23 km, Rs 9,158 crore). The Brihanmumbai Municipal Corporation (BMC) is constructing the Goregaon–Mulund Link Road tunnel (12.2 km), which will connect the western and eastern suburbs.

Together, these projects are expected to form a multi-layered network that relieves pressure on Mumbai’s surface roads and cuts commuting time between major districts.

Officials said that once the DPR is completed and approved, the project will move into execution, starting with the Worli–BKC–Airport section. Officials said each phase would be timed with traffic demand and city growth.

The tunnel network is expected to lower emissions, shorten trips between South Mumbai, BKC and the Airport, and make daily travel more predictable. For the MMRDA, the goal is straightforward: to create an underground expressway system that complements the metro and coastal corridors and provides Mumbai with breathing room on the surface.

This is about building capacity without taking more land, an official said. “If Mumbai has to keep growing, it needs to grow below the ground, too,” he added.