The construction work on India's longest (11.80 km) road tunnel linking Thane-Borivali - passing beneath the Sanjay Gandhi National Park (SGNP) is all set to start with the DPR already completed and the land acquisition process has also been fast-tracked. State PWD Minister Eknath Gaikwad informed that Maharashtra State Road Development Corporation (MSRDC) is executing the project, which will comprise a 10.25 km double tunnel and 1.55 km junction. It is estimated to cost about ₹11,235 crore with a deadline of 66 months.
The 6-lane twin tunnel (3 lanes in each direction) will enable vehicles to zip at 80-kmph. It will reduce the travel time from the current 60 minutes to barely 15 minutes between Borivali on the Western Express Highway to Thane, besides decongesting the Ghodbunder Road. The twin tunnel will run underneath the lush green SGNP for which the MSRDC is taking special precautions to avoid causing harm to its biodiversity or its flora and fauna. For this, the MSRDC will deploy Tunnel Boring Machines, similar to the ones deployed for digging the underground sections of Mumbai Metro projects, to cause minimum disturbances to wildlife in the 87-square km SGNP. As the first inter-district road tunnel project in the state, it will entail acquiring 16.54 hectares of private and 40.46 hectares of SGNP lands and will connect Borivali WEH in Mumbai with the Tikuji-ni-Wadi on the Thane side. The project will have cross-tunnels every 300 meters, drainage systems, smoke detectors, and jet fans to keep the air clean and fresh. It is expected to result in fuel savings of over a million lakh tons and reduce emissions by 36 per cent.