Franklin Line
The Franklin Line, part of the MBTA Commuter Rail system, runs from Boston's South Station in a southwesterly direction toward Franklin, Massachusetts, utilizing the Northeast Corridor before splitting off onto the namesake Franklin Branch.  Most Franklin Line trains connect to the Providence/Stoughton Line at , though some weekday trains use the Dorchester Branch (Fairmount Line) to access South Station.  Most weekday trains, and all weekend trains, bypass  and .  Several weekday trains originate at  or . 

Foxboro station is located on a branch line, which connects with the Franklin Line at Walpole. Previously, trains only served the station during special events at Gillette Stadium. In October 2019, the MBTA began one-year pilot program of full-time service, the Foxboro Line.

History

The earliest predecessor to the Franklin Line began in 1835 when the Boston and Providence Railroad built a branch from Dedham to Readville, connecting with the main line from Boston to Providence.  This was followed, in 1848, by the Norfolk County Railroad, which ran from Dedham to Walpole.  After various mergers and acquisitions, the line become part of the New York and New England Railroad until 1898, the New York, New Haven and Hartford Railroad until 1968, and, ultimately, Penn Central until its 1970 bankruptcy.  

What is today's Franklin Branch was a portion of the Midland Line of the New Haven's Midland Division, the New Haven's secondary route between Boston and New York; the MBTA's Dorchester Branch and the abandoned segments from Franklin to Willimantic, Connecticut via Blackstone were the remaining components of the Midland Line. In 1910, the passenger route on the Midland Line was a regional inter-city train that continued to New York via the Highland Line segment of the Highland Division between Willimantic and Waterbury, Connecticut, then continuing down the Housatonic Railroad to the New Haven Line. Service was eventually shortened to Waterbury in 1937. 

However, in the 1940s and early 1950s service, including the New Haven's Nutmeg and several unnamed trains from Boston to Hartford and Waterbury continued. It was shortened to Blackstone when the two southern spans of the bridge crossing the Quinebaug River in Putnam, Connecticut washed out during Hurricane Diane in 1955.  The bridge was never repaired, and the line was abandoned between Willimantic and Putnam in 1959.  

Service to Blackstone was discontinued in April 1966 when the MBTA began subsidizing the line; Franklin and beyond were not in the MBTA district, meaning that the towns themselves had to subsidize service, and only Franklin agreed to do so. The easternmost bridge over the Blackstone River in the March 17-19th flooding of the river; the line beyond Franklin was abandoned 3 years later, and is now preserved in full as the Southern New England Trunkline Trail.  Between 1973 and 1976, the Commonwealth of Massachusetts bought almost all track assets in Southeastern Massachusetts, including the Franklin Branch, from the Penn Central's bankruptcy trustees.

From the start of MBTA operations, Franklin was the terminus of the line.  Service was extended to Forge Park/495 station on June 2, 1988, although the line retained its original name. Forge Park/495 is not on the former NY&NE main line to Woonsocket, but instead on the former Milford & Woonsocket Railroad, which last saw passenger service in 1938. The MBTA leased the branch from Conrail for the extension, with the possibility of future purchase. In February 2020, the MBTA voted to purchase the line from Franklin to Milford for $13 million.

Double tracking
In early 2019, the MBTA begin installation of an additional  of double track -  of new track plus the conversion of an existing siding) - between  and . The project will be completed by the end of 2019, and placed into service in 2020. The $30 million construction of an additional phase and preliminary design of a third were announced in November 2019. Phase 2 will add  of double track between Franklin and Norfolk, with completion by the end of 2020; it will allow headways to drop from 45 to 35 minutes. Phase 3 is planned to complete double-tracking between Boston and Franklin, including the modification of several stations.

Foxboro service

In September 2010, the MBTA completed a study to determine the feasibility of extending regular commuter rail service to Foxboro station via the Franklin Line.  The study looked at extending some Fairmount Line service to Foxboro, running shuttle trains from Foxboro to Walpole, or a combination of both.  The MBTA planned to purchase
trackage prior to restoring service; the Framingham Secondary, which provides access to Foxboro station, was acquired by the MBTA effective June 17, 2015. (CSX Transportation, the former owner of the branch, retained trackage rights over it.)

In August 2017, the MBTA Fiscal Control Board approved an 11-month pilot program to test commuter rail service to Foxboro, with service planned to begin sometime in late 2018 or early 2019, although Fairmount Line advocates warned it might reduce service quality to existing Fairmount Line stations. In October 2017, the MBTA indicated that service would begin on May 20, 2019. Service during the trial period will consist of seven daily round trips - three during the morning peak period, three in the evening peak, and one midday. The launch date was later delayed to October 21, 2019.

By December 2019, daily boardings at Foxboro averaged 70 - one-third of the projected ridership.

Milford extension
In July 2011, the Boston Region Metropolitan Planning Organization began studying the viability of extending Franklin Line commuter rail service to Hopedale and Milford. The study would update a 1997 MBTA evaluation that concluded costs outweighed the benefits of a possible expansion.  Local officials believe increased population and track upgrades to the Grafton and Upton Railroad may increase the viability of an extension. 8 miles of track from Franklin Junction to Milford were leased by the MBTA from Conrail for the Forge Park/495 extension and to establish the possibility of future service to Milford. A 2004 analysis determined that the extension would cost $70.5 million and attract about 1,800 additional riders per weekday.

Station listing