Atal Setu opened to public traffic on 13 January 2024, the day after its inauguration. The six-lane Mumbai Trans Harbour Link, approximately 21.8 kilometres long, gave Mumbai and Navi Mumbai a new road across the harbour. A connection debated and planned over many years had become infrastructure that motorists could actually use. [1]
The project’s history reaches behind the foundation-stone ceremony. In February 2009, Maharashtra assigned ownership and implementation to the Mumbai Metropolitan Region Development Authority. In June 2011, the state designated it a regional development project. Those decisions placed the crossing within a wider effort to connect the island city with the mainland and support development around Navi Mumbai and Raigad. [1]
How the crossing was built
Prime Minister Narendra Modi laid the foundation stone in December 2016 and inaugurated the completed bridge in January 2024. The inauguration announcement put its cost at more than ₹17,840 crore. MMRDA’s record dates the start of work to March 2018 and completion to 5 January 2024. The central government’s involvement sat alongside the state authority’s implementation and the work of engineers, contractors and labourers. [1] [2]
Japanese finance was a substantial part of that undertaking. JICA reported three official development-assistance loan tranches, signed in 2017, 2020 and 2023, totalling ¥242.459 billion. Its January 2024 release expressed that as approximately ₹13,715 crore. The rupee equivalent in a lender’s announcement should not be confused with a final audited project account; nor was the loan a gift. [3]
JICA also described the collaboration between Indian and Japanese engineers and the use of orthotropic steel decks. The bridge’s completion was both a transport project and an example of the financing and technical cooperation behind India–Japan infrastructure ties. [3]
From forecast to traffic
At inauguration, JICA expected the journey between the two sides to fall from about an hour to 20 minutes. That was a forecast for the connection, not a measured promise for every door-to-door trip across the metropolitan region. Time spent reaching the bridge and leaving it remains part of a commuter’s journey. [3]
The first-year numbers offered an early indication of use. In January 2025, The Indian Express, citing MMRDA officials, reported about 83 lakh vehicle passages and average daily traffic of 22,689. Its report compared that with an opening-year expectation of 40,000 a day. Vehicle passages count use, including repeat journeys, rather than distinct beneficiaries. The figures establish substantial traffic while also showing that the initial forecast had not been reached. They describe that first year, not present-day demand. [4]
The harbour setting also carried environmental obligations beyond construction. JICA classified the project as Category A because of its potential for significant adverse impacts. Its disclosure register continued to list environmental monitoring reports after opening, including one covering July–December 2025. The bridge had entered service; the obligation to monitor its surroundings continued alongside the traffic. [5]