Among the key infrastructure projects promised in the Bharatiya Janata Party-led Mahayuti’s manifesto for Mumbai’s Brihanmumbai Municipal Corporation (BMC) polls is the speeding up of the Thane to Borivali
twin tunnel project. It is being built in the Mumbai Metropolitan Region to improve connectivity between Thane (on the eastern side of the region) and Borivali (on the western side). Once completed, it will bring down the travel time to 15 minutes.
“With an investment of ₹12,057 crore, split between ₹6,178 crore for the 5.75 km Borivali stretch and ₹5,879 crore for the 6.09 km Thane side, this tunnel will transform urban commute while ensuring environmental responsibility,” CM Devendra Fadnavis had earlier said in a post on X.
Thane to Borivali twin tunnel project
Implemented by the Mumbai Metropolitan Region Development Authority (MMRDA), the project consists of two parallel road tunnels (a twin-tube tunnel) running under the Sanjay Gandhi National Park (SGNP).
- Total length: 11.8 km
- Tunnel length: 10.25 km
- Connecting roads: 1.59 km
- Length division: Along Borivali — 5.75 km; Thane side — 6.09 km
- Each tunnel will carry three lanes of traffic (two traffic lanes and an emergency lane).
It is expected to be the longest urban road tunnel in the state of Maharashtra.
Connecting Cities, Cutting Emissions, and Creating Impact — The Twin Tunnel Vision!
Chaired a review meeting regarding the ‘Thane–Borivali Twin Tunnel Project’ — a transformative step towards seamless travel, faster commutes, and sustainable urban progress. Directed officials to… https://t.co/PlwZykTpS7
— Devendra Fadnavis (@Dev_Fadnavis) June 26, 2025
Why is it a BMC election promise?
Currently, the road distance between Thane and Borivali via Ghodbunder Road/Western Express Highway can take 60-90 minutes or more in heavy traffic.
The tunnel will create a direct underground link, cutting the travel time to around 15–20 minutes.
It’s intended to decongest traffic, reduce pollution, and support smoother mobility for daily commuters.
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Thane-Borivali twin tunnel project’s first TBM, S-1400A by Herrenknecht, has passed factory tests!
The 3 lane tunnels will have a maximum depth of 23 m… pic.twitter.com/xX0PWuNght
— Infra News India (INI) (@TheINIofficial) February 28, 2025
What is the plan?
Each tunnel will have two traffic lanes and one emergency lane. There will be cross-passages at every 300 meters.
From a safety point of view, the following facilities will be provided:
- Ventilation system
- Firefighting equipment
- Smoke detector devices
- Retro-reflective / LED information board
Use of Tunnel Boring Machines (TBMs) to minimise surface disruption, especially important because the alignment goes underneath the eco-sensitive Sanjay Gandhi National Park. The diameter of the cutter head will be 13.34 m, with length at 86 meters and weight at around 2,500 tonnes.
It will link the Ghodbunder Road (Thane side) with the Western Express Highway (Borivali), providing a faster route for commuters and reducing the load on existing road corridors.
A huge mobility leap for the Mumbai Metropolitan Region.
India’s largest and longest urban road tunnel, the Thane–Borivali Twin Tunnel Project, has just crossed a historic milestone.
MMRDA has successfully completed the Thane-side portal excavation and lowered the 13.34-metre… pic.twitter.com/TLQb6W08Y2
— MMRDA (@MMRDAOfficial) December 2, 2025
The deadline
Administrative approval was given in March 2023 and the construction began in May 2023. The project is expected to be completed by 2028.
There have been updates to the alignment and extension of access points to reduce congestion at local junctions.
Happy to inform that the National Board of Wildlife has granted approval to the #Thane #Borivalli Twin #Tunnel. This marks an important milestone in starting work of this watershed #project#RebootingMumbai #ReshapingMMR #MumbaiIsUpgrading #MMRDA #UrbanTransformation pic.twitter.com/E3ZqOAriWR
— Dr. Sanjay Mukherjee (@DrSanMukherjee) February 3, 2024
The cost
The total project cost is expected to be Rs 18,838 crore.
