Shore Line East (SLE) is a commuter rail service which operates along the Northeast Corridor through southern Connecticut, United States.

Proposals for future expansion include extensions to Westerly, Rhode Island, and Norwich, Connecticut, and an infill station in Niantic.

[9] The section of the Northeast Corridor that Shore Line East operates on was once the New York–Boston mainline of the New York, New Haven and Hartford Railroad.

It was replaced in April 1978 by the New Haven–Providence–Boston Beacon Hill, which made local stops including Branford, Madison, Old Saybrook, Niantic, New London, and Mystic.

[16] Based on the 1986 study, Governor William O'Neill ordered CTDOT in October 1986 to initiate rail service on the corridor.

Shore Line East was threatened to be cut in 1991 by newly elected Governor Lowell Weicker, but it proved more popular than expected, and was effectively made permanent.

A 1996 study found that Shore Line East captured eight percent of regional commuter trips and attracted a loyal ridership base.

[16] In 1995 and 1997, then-governor John Rowland proposed to replace Shore Line East and the Waterbury Branch with bus service, citing a high subsidy of $18.70 per rider per trip, in order to decrease the unpopular gas tax.

[19] The Shore Line East Rider's Association and other groups lobbied to save both services each time, and after public hearings a small fare increase was enacted in late 1997 instead.

[20] In July 1995, Governor Rowland signed a bill ordering various studies, including one that analyzed extending service to New London as had been originally planned.

[24] This trip was intended to allow commuters to reach employment centers in Bridgeport and Stamford without having to make a transfer at New Haven.

An agreement with the Connecticut Department of Energy and Environmental Protection limits service over the Amtrak Old Saybrook–Old Lyme Bridge in order to avoid inconveniencing recreational boaters.

[26] After criticism over the service cuts, in April 2008 CTDOT began allowing commuters with multi-ride passes to board the selected Amtrak trains as well.

[27] Because Shore Line East was intended to be a temporary service, the five intermediate stations built in 1990 were little more than wooden decks.

In January 2001, because of changes in Amtrak rules related to the introduction of Acela Express service, passengers were no longer allowed to cross tracks to access trains.

[33] The new Guilford station, which has platforms on both sides of the tracks (connected by a pedestrian bridge) to allow for greater operational flexibility, opened on November 28, 2005.

[38][39] On October 8, 2007, reverse-peak and more midday service were introduced, which officials hailed as the beginning of Shore Line East as a true bidirectional system.

[40] A pilot of weekend service was run from November 17, 2007, to December 30, 2007, with six "Shopper's Special" round trips from Old Saybrook to New Haven.

[45] In July 2012, then-governor Dannel Malloy announced that five weekend round trips would be extended to New London beginning in April 2013.

[46] Two weekday midday trips were added in May 2013, while weekend service began on June 1, 2013, after the application for additional bridge closings was approved by the state Department of Energy and Environmental Protection.

[49] In a 2007 report, CTDOT outlined plans to turn SLE into a full-service bidirectional regional rail line, with full-day service and all trains extended to New London.

[35][61]) Expansion of the original parking facilities was also necessary to meet demand, since many started with small lots suitable for just a few dozen cars.

An Amtrak track maintenance project required single-tracking of sections of the line, and CTDOT lacked sufficient functional locomotives as the aging fleet was sent out for refurbishment.

[63] Three weekday round trips were reverted from bus to train in January 2019 when one locomotive returned from refurbishment, though additional issues were expected during a second summer of track work in 2019.

[80] Ultimately, MBTA Commuter Rail service, which already ran to Providence as part of the Providence/Stoughton Line, was extended southward instead (although only to Wickford Junction).

[4] As part of Malloy's 2015 30-year transit plan, Shore Line East was to be extended to Westerly at a cost of $200 million.

[81] In February 2016, the state public transportation commission issued a report recommending extension of Shore Line East rail service to Mystic and Westerly as soon as possible.

The study also analyzed potential service to Norwich via the Palmer Line (New England Central Railroad mainline) with intermediate stations at Connecticut College/U.S.

[85] In April 2012, state officials released a report detailing possible sites for an infill station in East Lyme.

These cars are part of a larger fleet, jointly owned by the state and the Metropolitan Transportation Authority, that operate on the Metro-North Railroad New Haven Line and New Canaan Branch.