Coastal Road [2] is an 8-lane, 29.2-km long grade separated expressway along Mumbai's western coastline connecting Marine Lines in the south to Kandivali in the north.

[3] It is projected to be used by 130,000 vehicles daily, and is expected to reduce travel time between South Mumbai and the Western Suburbs from 2 hours to only 40 minutes.

Its first phase, which was inaugurated on 11 March 2024, is a 10.58 km section from Princess Street flyover to the Worli end of the Bandra–Worli Sea Link.

[4][5] In 2011, Maharashtra Chief Minister Prithviraj Chavan proposed the Coastal Road as an alternative to the plan for the Western Freeway.

He appointed a Joint Technical Committee, comprising experts and officials, in 2012 under the then municipal commissioner Subodh Kumar to study the plan to build a coastal road.

In its report, submitted in January 2012, the committee advised the government to build a 35.6 km coastal freeway from Manora MLA Hostel at Nariman Point to Kandivali to ease traffic congestion.

After discussing the project on 10 April 2013, the Maharashtra Coastal Zone Management Authority (MCZMA), the state's apex environment body, urged the centre to amend the CRZ notification to permit "reclamation for roads".

Fishermen demanded a larger span of 200 metres as they felt the smaller gap would not be sufficient for boats particularly during strong waves.

Chief Minister Eknath Shinde had directed BMC authorities in January 2023 to construct the pillars at a span of 120 metres instead.

[27] A 7.47 km long and 20 metre wide contiguous promenade runs parallel to the Coastal Road, on its seaward side, from Priyadarshini Park to the Worli end of the Bandra–Worli Sea Link.

The BMC also placed boulders, weighing between 2-8 tonnes, obtained from the Navi Mumbai International Airport construction site along the seaface.

[32] A tunnel was selected for this stretch over a sea link to avoid disrupting the view at the Queen's Necklace and Girgaon Chowpatty and to preserve the "heritage, the look and feel of this place".

[39] The first phase of the project is a 10.58 km section from Princess Street Flyover at Marine Lines to the Worli-end of the Bandra–Worli Sea Link (BWSL).

[25] The project cost escalated to ₹13,060 crore (US$1.5 billion) due to an increase in the GST rate on construction from 12% to 18%, and the need to shift a water pipeline that had not been accounted for in the original design.

Package 1 includes the construction of a 3.82 km long section over reclaimed land from Priyadarshini Park to Baroda Palace and interchanges at Amarson Garden and Haji Ali.

Package 4 includes the construction of a 3.93 km section from Princess Street flyover to Priyadarshini Park, including the up and down ramps from Marine Drive connecting to the twin tunnels passing below Girgaum Chowpatty, Malabar Hills, and exit at Priyadarshini Park to connect with section in Package 1.

[42][43] Packages 2 and 3 involves a bridge spanning 0.9 km, an interchange, a 3.2-km-long ramp and a 1.9-km embankment between Baroda Palace near Haji Ali and the Worli end of Bandra–Worli Sea Link.

Nine petitioners moved the Bombay High Court seeking to halt construction alleging that land reclamation was illegal and would irreversibly alter the coastal environment.

The agency stated that it had received all required permissions to carry out construction and that delay due to the stay order was causing a loss of ₹10 crore (US$1.2 million) per day.

[50] BMC officials stated on 14 May that round-the-clock construction had resumed at all project sites covered by the Supreme Court's order.

Due to the delays caused by the Court case, the agency stated that it would continue construction throughout the monsoon season whenever it was possible to do so without impacting marine life.

[56][57][58] On 16 July, the Bombay High Court cancelled the approval granted by MCZMA and by the MoEF to the Coastal Road project citing a lack of "proper scientific study".

CRCHIL staff were scheduled to visit Mumbai to assemble the TBM, however, they were unable to do so due to COVID-19 pandemic related travel restrictions.

[76] On 3 August 2022, L&T announced that Mavala had set a world record for longest distance excavated in a month by a Single Shield EPB TBM.

The Mangrove and Marine Biodiversity Conservation Foundation of Maharashtra conducted a 4 month study during monsoon season in 2019 to identify coral species living along Mumbai's western coastline that could be affected by the land reclamation for the Coastal Road project.

[82] The Union Environment Ministry and the Maharashtra Forest Department granted permission to relocate two coral species from Worli to a site 200 metres away from the Coastal Road and from Haji Ali to a protected zone in Navy Nagar.

[83] The National Institute of Oceanography (NIO) began the relocation process on 12 November 2020,[82] and a total of 329 colonies of corals were shifted.

[87] The Coastal Road will begin from BD Somani Chowk, 280 metres south of the Princess Street Flyover.

[89] Following the opening on phase 1, due to safety considerations, only passenger cars, and BEST/State Transport buses are allowed to ride on the Coastal Road.

Heavy vehicles such as trucks and trailers, two and three-wheelers, pedestrians, and animal drawn carriages will not be permitted to use the Coastal Road.