View source for Green Line (MBTA)

{{Short description|Light rail system}}
{{Use American English|date=February 2025}}
{{Use mdy dates|date=December 2022}}
{{Infobox rail line
| name                            = Green Line
| color                           = {{rcr|MBTA|Green}}
| image                           = MBTA Green Line Type 9 Train at Park Street August 2024.jpg
| image_width                     = 320px
| caption                         = Green Line train at [[Park Street station (MBTA)|Park Street station]] in 2024
| type                            = [[Light rail]]
| system                          = [[MBTA subway]]
| locale                          = [[Boston]], [[Brookline, Massachusetts|Brookline]], [[Cambridge, Massachusetts|Cambridge]], [[Medford, Massachusetts|Medford]],  [[Newton, Massachusetts|Newton]], and [[Somerville, Massachusetts]]
| start                           = '''North/east terminals''':{{ubl|[[Union Square station (Somerville)|Union Square]] ([[Green Line D branch|D]])|{{bts|Medford/Tufts}} ([[Green Line E branch|E]])|{{bts|Government Center}} ([[Green Line B branch|B]] and [[Green Line C branch|C]])}}
| end                             = '''South/west terminals''':{{ubl|{{bts|Boston College}} ([[Green Line B branch|B]])|{{bts|Cleveland Circle}} ([[Green Line C branch|C]])|{{bts|Riverside}} ([[Green Line D branch|D]])|{{bts|Heath Street}} ([[Green Line E branch|E]])}}
| stations                        = 70<!-- 11 Lechmere–Kenmore, 16 B, 13 C, 13 D, 11 E, 1 US, 5 M/T-->
| routes                          = 4 ([[Green Line B branch|B&nbsp;branch]], [[Green Line C branch|C&nbsp;branch]], [[Green Line D branch|D&nbsp;branch]], [[Green Line E branch|E&nbsp;branch]])
| daily_ridership                 = 101,000 (2023)<ref>{{cite web |url=https://cdn.mbta.com/sites/default/files/2024-08/7.%20History%20of%20Funding%20Updated%20V16%208.21.24.pdf |date=August 22, 2024 |first1=Mary Ann |last1=O'Hara |first2=Pat |last2=Turners |publisher=Massachusetts Bay Transportation Authority |page=2 |title=History of Funding Update}}</ref>
| open                            = {{Start date|1897|09|01}} ([[Tremont Street subway]])
| close                           = 
| owner                           = [[Massachusetts Bay Transportation Authority]]
| operator                        = 
| character                       = Subway, grade-separated surface [[Right-of-way (transportation)|ROW]], viaduct, median reservation, [[street running]]
| stock                           = [[Kinki Sharyo]] [[MBTA Kinki Sharyo Type 7|Type 7]]<br />[[Hitachi Rail Italy|AnsaldoBreda]] [[MBTA AnsaldoBreda Type 8|Type 8]]<br />[[Construcciones y Auxiliar de Ferrocarriles|CAF]] [[MBTA CAF USA Type 9|Type 9]]
| linelength                      = {{convert|26.7|mi}} <ref name=bluebook /><!--4.23 B, 2.90 C, 9.35 D, 2.43 E, 3.66 Kenmore-Lechmere, 0.37 Lechmere-RBJ, 0.71 US, 3.04 MT--><!--4.23 B, 2.90 C, 9.35 D, 2.43 E, 3.66 Kenmore-Lechmere, 0.37 Lechmere-RBJ, 0.71 US, 3.04 MT-->
| tracklength                     = 
| tracks                          = 
| gauge                           = {{track gauge|ussg|allk=on}}
| minradius                       = {{convert|10|m|ft|0|abbr=out|order=flip}}<ref name=lowfloorreport>{{cite web|url=http://onlinepubs.trb.org/Onlinepubs/tcrp/tcrp_rpt_02.pdf|title=Applicability of Low-Floor Light Rail Vehicles in North America|publisher=Transit Cooperative Research Program |author=Booz • Allen & Hamilton Inc.|year=1995|access-date=August 7, 2013}}</ref>
| electrification                 = {{600 V DC|conductor=overhead}}
| speed                           = 
| map                             = {{switcher
|{{maplink-road|from1=Green Line B branch.map|from2=Green Line C branch.map|from3=Green Line D branch.map|from4=Green Line E branch.map}}
|Show interactive map
|{{MBTA Green Line|inline=1}}
|Show route diagram map
}}
| map_state                       = 
}}

The '''Green Line''' is a [[light rail]] system<ref>{{Cite web |title=Green Line Transformation (GLT) Program Project Development Profile: FY 2024 Annual Report |url=https://www.transit.dot.gov/funding/grants/grant-programs/capital-investments/green-line-transformation-glt-program-project |website=Federal Transit Administration}}</ref><ref>{{Cite web |title=Green Line D Track and Signal Replacement {{!}} Projects {{!}} MBTA |url=https://www.mbta.com/projects/green-line-d-track-and-signal-replacement |access-date=2025-04-05 |website=www.mbta.com}}</ref> run by the [[Massachusetts Bay Transportation Authority]] (MBTA) in the [[Boston]], [[Massachusetts]], metropolitan area. It is the oldest [[MBTA subway]] line, and with tunnel sections dating from 1897, the oldest subway in [[North America]].<ref name=dougmost>{{cite web |url=https://www.bostonglobe.com/magazine/2014/01/26/the-history-behind-boston-race-build-america-first-subway/jm0grRaspdAREUbDv4KXsI/story.html|title =The bigger dig|date=January 26, 2014|access-date=January 22, 2016|last=Most |first=Doug|publisher=Boston Globe}}</ref> It runs underground through downtown Boston, and on the surface into inner suburbs via six branches on radial boulevards and grade-separated alignments. With an average daily weekday ridership of 101,000 in 2023, it is [[List of United States light rail systems by ridership|among the most heavily used light rail systems in the country]]. The line was assigned the green color in 1967 during a systemwide rebranding because several branches pass through sections of the [[Emerald Necklace]] of Boston.<ref name=netransit /><ref>{{cite book |url=http://web.mit.edu/cron/project/uncertainty/Dowd_Data/Baum_Snow/boston-history.txt |title=A Chronicle of the Boston Transit System |year=1992 |publisher=Massachusetts Bay Transportation Authority |via=MIT |last=Sanborn |first=George M. |access-date=January 21, 2016 |archive-date=November 27, 2019 |archive-url=https://web.archive.org/web/20191127202604/http://web.mit.edu/cron/project/uncertainty/Dowd_Data/Baum_Snow/boston-history.txt |url-status=dead }}</ref><ref>{{cite web |url=http://www.mbta.com/uploadedfiles/Smart_Forms/News,_Events_and_Press_Releases/Curiosity_Carcard-opt9a-FINAL.pdf |title=Curiosity Carcards |publisher=Massachusetts Bay Transportation Authority |access-date=January 21, 2016 |archive-date=February 18, 2017 |archive-url=https://web.archive.org/web/20170218124607/http://www.mbta.com/uploadedfiles/Smart_Forms/News,_Events_and_Press_Releases/Curiosity_Carcard-opt9a-FINAL.pdf |url-status=dead }}</ref>

The four branches are the remnants of a large [[streetcar]] system, which began in 1856 with the [[Cambridge Horse Railroad]] and was consolidated into the [[Boston Elevated Railway]] several decades later. The branches all travel downtown through the [[Tremont Street subway]], the oldest subway tunnel in North America. The Tremont Street subway opened its first section on September 1, 1897, to take streetcars off overcrowded downtown streets; it was extended five times <!-- 1898, 1912, 1914, 1932, 1941--> over the next five decades. The streetcar system peaked in size around 1930 and was gradually replaced with [[Trolleybuses in Greater Boston|trackless trolleys]] and [[MBTA bus|buses]], with cuts as late as 1985. The new [[Green Line D branch|D branch]] opened on a converted commuter rail line in 1959. The [[Green Line Extension]] project extended two branches into [[Somerville, Massachusetts|Somerville]] and [[Medford, Massachusetts|Medford]]&nbsp;in 2022.

==Route description==
[[File:MBTA Green Line.svg|thumb|right|upright=2.0|Schematic map of Green Line branches and stations]]
The Green Line's core is the [[central subway (Boston)|central subway]], a group of tunnels which run through downtown Boston.<ref name=3carplan>{{cite web |url=http://dspace.mit.edu/bitstream/handle/1721.1/74271/813791269.pdf |title=MBTA Green Line 3-Car Train Operating Plans to Enhance Reliability and Capacity (Master's Thesis) |publisher=Massachusetts Institute of Technology Department of Civil and Environmental Engineering |author=Malikova, Alexandra A. |date=June 2012 |access-date=August 7, 2013}}</ref> The [[Tremont Street subway]] runs roughly north–south through downtown, with stations at {{bts|Boylston}}, {{bts|Park Street}}, {{bts|Government Center}}, {{bts|Haymarket}}, and {{bts|North Station|Green}} – all with connections to other lines of the [[MBTA subway]] system. The [[Boylston Street subway]] runs roughly east–west through the [[Back Bay, Boston|Back Bay]] neighborhood, with stations at {{bts|Arlington}}, {{bts|Copley}}, {{bts|Hynes Convention Center}}, and {{bts|Kenmore}}; it connects to the Tremont Street subway at Boylston. The [[Huntington Avenue subway]] diverges from the Boylston Street subway at a flat junction west of Copley, running southwest, with stations at {{bts|Prudential}} and {{bts|Symphony}}.<ref name=linesofthehub>{{cite book |title=Streetcar Lines of the Hub – The 1940s |last=Clarke |first=Bradley H. |year=2003 |publisher=Boston Street Railway Association |isbn=0938315056 }}</ref>{{rp|96}} A branch of the Tremont Street subway, disused since 1962, runs south from Boylston to the former [[Pleasant Street incline]].

The Green Line has four western surface branches, each with a letter designation:
*The [[Green Line B branch|B branch]] runs west in a tunnel from Kenmore, surfacing in the median of [[Commonwealth Avenue (Boston)|Commonwealth Avenue]] at {{bts|Blandford Street}}. It runs {{convert|4.2|miles}} on Commonwealth Avenue through [[Boston University]], Allston, and Brighton to [[Boston College station]]. 
*The [[Green Line C branch|C branch]] runs southwest in a tunnel from Kenmore, surfacing in the median of [[Beacon Street (Boston)|Beacon Street]] at {{bts|Saint Mary's Street|C}}. It runs {{convert|2.9|miles}} on Beacon Street through [[Brookline, Massachusetts|Brookline]] to [[Cleveland Circle station]]. 
*The [[Green Line D branch|D branch]] diverges from the C branch tunnel southwest of Kenmore, surfacing at [[Fenway station]]. It runs {{convert|9.7|miles}} though Brookline and [[Newton, Massachusetts|Newton]] along the [[grade separation|grade-separated]] [[Highland branch]] (a former [[Boston and Albany Railroad]] [[commuter rail]] line) to [[Riverside station (MBTA)|Riverside station]]. 
*The [[Green Line E branch|E branch]] runs southwest through the Huntington Avenue subway from Copley, surfacing in the median of [[Huntington Avenue]] at [[Northeastern University station]]. It runs {{convert|2.6|miles}} along Huntington Avenue and South Huntington Avenue to {{bts|Heath Street}}, with the outer {{convert|0.7|miles}} (west of {{bts|Brigham Circle}}) in [[street running|mixed traffic]] rather than a dedicated median. Until 1985, the line continued south through [[Jamaica Plain]] to {{bts|Arborway}}.<ref name="netransit">{{NETransit}}</ref>

B and C branch service terminates at Government Center, while D and E branch service continues north from downtown Boston. North of [[North Station]], the line inclines up to the [[Lechmere Viaduct]], which crosses the [[Charles River]] with an elevated station at {{bts|Science Park}}. The elevated [[Lechmere station]] is located on the [[Green Line Extension]] viaduct, which continues north to a flying junction with two branches:
*The Union Square Branch runs {{convert|0.7|miles}} west to [[Union Square station (Somerville)|Union Square station]] via the [[Fitchburg Line]] right-of-way. It is operated as part of the D branch.
*The Medford Branch runs {{convert|3.0|miles}} northwest to [[Medford/Tufts station]] via the [[Lowell Line]] right-of-way. It is operated as part of the E branch.

===Former branches===
{{main list|Boston-area streetcar lines}}<!--A more complete list of services running into the subway is in the green rows on [[Boston-area streetcar lines]].-->

The [[Green Line A branch]] was the northernmost of the branches, running from the [[Blandford Street (MBTA station)#History|Blandford Street portal]] (still used by the B branch), west to [[Watertown Square (MBTA station)|Watertown]], mostly [[street-running]]. The {{MBTABus|57}} bus replaced the streetcar line in 1969. The A branch diverged from Commonwealth Avenue west of Boston University and ran to a terminus in [[Watertown Square (MBTA station)|Watertown]], across the Charles River from Watertown Square, until 1969. Although the route-letter scheme had been introduced two years prior to its closure, the "A" designation was never signed on streetcars to [[Watertown, Massachusetts|Watertown]]. It was, however, included in the [[destination sign]]s on the [[US Standard Light Rail Vehicle|Boeing-Vertol LRV]]s ordered in the mid-1970s, when reopening service to Watertown was under consideration. The "A" line tracks remained in non-revenue service to access maintenance facilities at Watertown until 1994.

The [[Pleasant Street portal]] hosted two services in its final days. The {{MBTABus|9}} to [[City Point (MBTA station)|City Point]] ended in 1953, and the {{MBTABus|43}} to [[Egleston (MBTA station)|Egleston]] was cut back to [[Lenox Street (MBTA station)|Lenox Street]] in 1956, cut back to the portal in 1961, and ended operation in 1962. Prior to that, the {{MBTABus|48}} serviced Tremont Street to Dover Street and [[Washington Street (Boston)|Washington Street]], ending at {{bts|Dudley}}, and last running in 1938.

The last two routes to continue beyond the [[Canal Street portal]] both ran to [[Sullivan Square (MBTA station)|Sullivan]]. The {{MBTABus|92}} ran via Main Street, last running in 1948, and the {{MBTABus|93}} via Bunker Hill Street last ran in 1949. Until 1997, trains continued to use the portal and its North Station surface station as a terminal.

In addition to the lines that later became the E branch, the predecessors to the {{MBTABus|58}} and {{MBTABus|60}} split in [[Brookline, Massachusetts|Brookline]], one branch running into the current "E" tracks and into the [[Boylston Street portal]], and the other running up [[Brookline Street (Boston)|Brookline Street]] to end at [[Hynes Convention Center (MBTA station)|Massachusetts Avenue]] station. These were truncated in 1932 into a shorter route from [[Brookline Village (MBTA station)|Brookline Village]] to the subway via the Boylston Street portal, which itself stopped running in 1938 (being cut back to [[Brigham Circle (MBTA station)|Brigham Circle]] short-turn trips), three years before the closure of that portal.

The last "foreign" cars to operate in the subway were those of the [[Eastern Massachusetts Street Railway]], running from the [[Canal Street portal]] to the [[Brattle Loop]] at [[Government Center (MBTA station)|Scollay Square]] until 1935. It was then that the old [[Mystic River Bridge]] to [[Chelsea, Massachusetts|Chelsea]] was closed to streetcars and the lines were replaced by bus service; the next year the [[Boston Elevated Railway]] (BERy) bought the Eastern Mass Chelsea Division and through-routed it with its lines connecting to the [[East Boston Tunnel]] at [[Maverick (MBTA station)|Maverick]].

== Rolling stock ==
Like the three other MBTA subway lines, the line uses [[standard gauge]] tracks. However, instead of heavy rail metro rolling stock, the Green Line uses modern streetcars (light rail vehicles) as heavy rail stock would be inappropriate for the surface branches with their numerous [[grade crossings]].

===Listing===
====Active fleet====
Rolling stock {{as of|June 2024|lc=yes}}:<ref name=bluebook>{{MBTA Bluebook 2014}}</ref><ref name=roster />
{| class="wikitable"
|-
!Year Built
!Manufacturer
!Model
!Image
!Length
!Width
!Fleet Numbers
!Quantity
|-
| 1986–1988
| rowspan=2 | [[Kinki Sharyo]]
| rowspan=2 | [[MBTA Kinki Sharyo Type 7|Type 7 LRV]]
| [[File:MBTA Green Line 3634 at Newton Highlands station.jpg |100px]]
| rowspan=2 | {{convert|72|ft|m|sigfig=2|abbr=on}}
| rowspan=4 | {{convert|104|in|m|sigfig=3|abbr=on}}
| 3600–3699
| 100 (78 active, all overhauled)
|-
| 1997
| [[File:Inbound train at Kenmore station, July 2019.JPG|100px]]
| 3700–3719
| 20 (15 active, all overhauled)
|-
| 1998–2007
| [[Hitachi Rail Italy|AnsaldoBreda]]
| [[MBTA AnsaldoBreda Type 8|Type 8 LRV]]
| [[File:MBTA Green Line B.jpg|100px]]
| rowspan="2" | {{convert|74|ft|m|sigfig=2|abbr=on}}
| 3800–3894
| 95 (80 active)
|-
|2018–2020
|[[Construcciones y Auxiliar de Ferrocarriles|CAF USA]] 
|[[MBTA CAF USA Type 9|Type 9 LRV]]
| [[File:Type 9 on Reservoir yard leads, March 2022.JPG|100px]]
| 3900–3923
| 24 (all active)
|}

==== Retired fleet ====
Only MBTA operated vehicles are included here, not cars from the Boston Elevated Railway era.

{| class="wikitable"
|-
!Years in Service
!Manufacturer
!Model
!Image
!Length
!Width
!Fleet Numbers
!Quantity
|-
| 1976–2007
| [[Boeing Vertol]]
| [[US Standard Light Rail Vehicle]]
| [[File:1977 Boeing LRV 3466 of MBTA (Boston) at Beacon and Hawes in 1987.jpg|100px]]
| {{convert|71|ft|m|sigfig=2|abbr=on}}
| {{convert|104|in|m|sigfig=3|abbr=on}}
| 3400–3543
| 144 (31 units cancelled)
|-
| 1937–1985{{efn|10 PCC streetcars are currently in revenue service on the [[Mattapan Line]].}} 
| [[Pullman Standard]]
| [[PCC streetcar]]
| [[File:PCC streetcars at Arborway Yard, June 1983.jpg|100px]]
| {{convert|48|ft|m|sigfig=2|abbr=on}}
| {{convert|100|in|m|sigfig=3|abbr=on}}
| 3000–3346
| 344 (2 cars scrapped before 1964)
|}

{{notelist}}

===History===
====Early rolling stock====
[[File:MBTA 3275 leaving Riverside Terminal, September 1965.jpg|thumb|right|PCC streetcars on the D branch in 1965]]
When it opened at the end of the 19th century, the Tremont Street subway was not intended as a full-scale rapid transit line (though it was built to [[semi-metro]] standards), but to allow ordinary streetcars to bypass the worst street congestion in downtown Boston.<ref name=dougmost /><ref name="1976report">{{cite web |author=Diamant, Emanuel S. |display-authors=etal |date=Spring 1976 |title=Light Rail Transit : A State of the Art Review |url=https://archive.org/details/lightrailtransit00diam |access-date=August 7, 2013 |publisher=United States Department of Transportation}}</ref> Operations by several different companies were eventually consolidated into the Boston Elevated Railway, which ran a mixture of car types. After receiving a test unit in 1937, the BERy began to standardize on [[PCC streetcar]]s, acquiring 320 units between 1941 and 1951 plus an additional 25 in 1959 to phase out the last older cars.<ref name=roster>{{cite web |url=http://www.transithistory.org/roster/ |title=The MBTA Vehicle Inventory Page |publisher=NETransit |access-date=September 23, 2018}}</ref> Beginning in 1923, all streetcars on the system were painted orange for maximum visibility in traffic. In 1971, the MBTA began painting Green Line streetcars in a green and white scheme to match the new line name.<ref>{{cite magazine |title=This Time In History |page=14 |magazine=Rollsign |date=September–October 2021 |volume=58 |issue=9/10 |issn=0035-7898 |publisher=[[Boston Street Railway Association]]}}</ref>

Two older streetcars are on display on the unused outer inbound track at Boylston station, which formerly carried cars coming from the [[Pleasant Street portal]]. Car #5734, a Type 5 A-1 car built in 1924 and retired in 1959, is owned by the [[Seashore Trolley Museum]], but resides semipermanently in Boston. PCC #3295, built in 1951 and retired in 1986, is owned by the MBTA.<ref name=roster /> The cars were formerly used for [[fantrip]]s, the most recent one being in 1998.

====Boeing LRV====
{{Main|US Standard Light Rail Vehicle}}
[[File:Boeing USSLRV (MBTA 3523).jpg|thumb|left|Boeing LRV on the C branch in 2005]]

In the early 1970s, [[light rail]]—which had largely disappeared from North America after the slow decline of streetcar systems from the 1920s to the 1950s—was reintroduced as a method of [[urban renewal]] less expensive than conventional metro systems.<ref name=thompson /> In 1971, as part of a program to supply further work to defense contractors as the [[Vietnam War]] wound down, the [[Urban Mass Transit Administration]] selected [[Boeing Helicopters|Boeing Vertol]] as systems manager for a project to design a new generic light rail vehicle. The UMTA hoped that this "[[US Standard Light Rail Vehicle]]" would jumpstart the development of transit lines just as the standardized PCC streetcars had done decades prior.<ref name=boeing>{{cite web |url=http://www.boeing.com/boeing/history/boeing/lightrail.page |title=History: Light Rail Vehicle/Rapid Transit Car |publisher=Boeing |access-date=August 7, 2013}}</ref>

Boston (with its older streetcar tunnel systems) and San Francisco (with a new [[Muni Metro]] streetcar tunnel being built as part of [[Bay Area Rapid Transit|BART]] construction) were chosen as the testbeds for this new rolling stock.<ref name=thompson>{{cite web |url=http://onlinepubs.trb.org/onlinepubs/circulars/ec058/03_01_Thompson.pdf |title=Defining an Alternative Future: Birth of the Light Rail Movement in North America |author=Thompson, Gregory L. |publisher=Transportation Research Board |date=November 2003 |access-date=August 7, 2013}}</ref><ref>{{cite report |url=https://rosap.ntl.bts.gov/view/dot/30467 |title=Light Rail Transit Systems: A Definition and Evaluation |author=Vuchic, Vukan R. |date=October 1972 |publisher=Urban Mass Transportation Administration, US Department of Transportation |access-date=20 December 2018}}</ref> The vehicle was designed as the largest rolling stock that would fit through the Tremont Street tunnel, the Muni Metro's [[Twin Peaks Tunnel]], and [[SEPTA]]'s [[SEPTA subway–surface trolley lines|subway–surface lines tunnel]].<ref name="1976report" /> The new cars were faster—a top speed of {{convert|50|mph|kph}} versus the PCC's {{convert|36|mph|kph}}—and had an articulated middle section for higher capacity.<ref name=1976report />

Boeing began construction of 175 cars for the MBTA in May 1973.<ref name="boeing" /> The first LRVs entered service on the D branch in December 1976 but were immediately beset with problems. Certain cars frequently derailed on tight turns in the Riverside, Boston College and Lechmere yards. Battery trays, air conditioners—mounted under the cars, continually drawing in dirt and debris from under the car when in the tunnels—and air compressors all suffered numerous failures; the plug-style doors had trouble sealing properly; and traction motors failed sooner than expected.<ref name=crisis>{{cite web |url=http://members.aol.com/netransit/private/LRV.html |archive-url=https://web.archive.org/web/20040406164315/http://members.aol.com/netransit/private/LRV.html |archive-date=April 6, 2004 |title=Boston's Green Line Crisis |publisher=NETransit |author=Moore, Scott |access-date=August 7, 2013}}</ref>

Desperate for reliable rolling stock, in 1977 MBTA launched an overhaul program to extend the availability of its older PCC cars. A total of 34 cars, primarily out-of-service wrecks and parts cars, were rebuilt to as-new condition.<ref name="crisis" /> {{As of|2022}}, some of these rebuilt PCC cars still run on the [[Mattapan Line]].<ref name="roster" /><ref name="crisis" />

After years of fighting between the MBTA and Boeing-Vertol, both sides reached a settlement in 1979. MBTA was allowed to reject the final 40 SLRVs, and Boeing would return $40&nbsp;million to MBTA for the cost of repairs and modifications to several cars.<ref name="GAO-MBTA-80">{{cite report |url=https://www.gao.gov/assets/140/130883.pdf |title=Massachusetts Bay Transportation Authority's Termination of Contract for Light Rail Vehicles PSAD-81-11 |author=Sheley Jr., W. H. |date=November 10, 1980 |publisher=United States General Accounting Office |access-date=22 December 2018}}</ref><ref name="TheyKnewAboutIt">{{cite news |last=Sullivan |first=Kathleen |date=September 14, 1998 |title=Muni knew about trolley lemons in '70s: Test runs in Boston found major trouble in many systems |page=A |newspaper=[[The San Francisco Examiner]] |url=http://www.sfgate.com/default/article/Muni-knew-about-trolley-lemons-in-70s-3070106.php |access-date=December 7, 2012}}</ref>

====Modern fleet====
[[File:Tappan Street with trains.JPG|thumb|Type 7 (left) and Type 8 streetcars at Tappan Street in 2012]]

In the early 1980s, with a final settlement with Boeing in place, MBTA started looking for new equipment to supplement and replace the problematic LRVs.

In 1980, the MBTA tested [[Canadian Light Rail Vehicle]]s for three months to determine whether they could be used on the Green Line.<ref>{{cite book |url=https://archive.org/details/chronicleofbosto00mass |title=A Chronicle of the Boston Transit System |publisher=Massachusetts Bay Transportation Authority |year=1981 |page=14 |via=Internet Archive}}</ref> The MBTA ultimately found them unsuitable.

Ultimately, the MBTA purchased LRVs from the Japanese firm [[Kinki Sharyo]]. These Type 7 were designed with the best features of the US SLRV, the Canadian LRV, and the PCC cars. A total of 120 Type 7 vehicles were purchased, 100 were delivered between 1986 and 1988, and an additional 20 cars ordered and delivered in 1997.<ref name="KINKOSHARYO">{{cite web |title=Boston – MBTA: Green Line – Technical Data |url=http://www.kinkisharyo-usa.com/media/pdf/boston.pdf |url-status=dead |archive-url=https://web.archive.org/web/20140720134931/http://www.kinkisharyo-usa.com/media/pdf/boston.pdf |archive-date=July 20, 2014 |access-date=August 7, 2013 |publisher=Kinki-Sharyo}}</ref>

Low-floor LRVs were added starting in 1998, allowing for accessible boarding directly from slightly raised platforms. MBTA ordered 100 of these Type 8 cars from [[Italy|Italian]] company [[Hitachi Rail Italy|AnsaldoBreda]].<ref name="roster" /> The first Type 8s entered revenue service in March 1999, and quickly proved problematic and difficult to maintain: the first cars failed every {{convert|400|mi}}, far short of the {{convert|9000|mi}} specified by the MBTA, and were prone to derailment at higher speeds as well as brake problems, echoing the problems with the Boeing stock. In December 2004, the MBTA canceled orders for the cars still to be delivered as part of the authority's nine-year, US$225&nbsp;million deal with Breda.<ref>Flint, Anthony. "[http://www.boston.com/news/local/massachusetts/articles/2004/12/12/mbta_halts_purchase_of_green_line_lemons?mode=PF MBTA Halts Purchase of Green Line 'Lemons']" ([https://web.archive.org/web/20050429133251/http://www.urbanplanet.org/forums/index.php?showtopic=7451 mirrored copy]). ''[[The Boston Globe]]''. December 12, 2004.</ref> One year later, in December 2005 the MBTA announced that it had entered into a restructuring of the deal, reducing the order to 85 cars (with spare parts to be provided in lieu of the 15 remaining cars), and providing for the remaining payment under the original deal only if the cars met performance requirements.<ref>{{cite news|url=http://www.boston.com/news/local/massachusetts/articles/2005/12/17/green_line_seeks_zippier_service_with_upgrade_plan |work=The Boston Globe |title=Green Line seeks zippier service with upgrade plan |first=Mac |last=Daniel |date=December 17, 2005 |url-status=dead |archive-url=https://web.archive.org/web/20070125235724/http://www.boston.com/news/local/massachusetts/articles/2005/12/17/green_line_seeks_zippier_service_with_upgrade_plan |archive-date=January 25, 2007 }}, archived as of January 25, 2007</ref> Construction of the last car under the order was completed on December 14, 2006.<ref>{{cite news|url=http://www.boston.com/news/local/startsandstops/blog/2006/12/bredas.html |work=The Boston Globe |title=Bredas |date=December 14, 2006 |url-status=dead |archive-url=https://web.archive.org/web/20070124072507/http://www.boston.com/news/local/startsandstops/blog/2006/12/bredas.html |archive-date=January 24, 2007 }} archived as of January 24, 2007</ref> Ultimately, 10 additional cars would be assembled and delivered in late 2007, with five spare shells retained (95 cars in service). The MBTA was criticized for their failure to assess Bredas' reliability before entering into the deal, and during delivery. The agency was also forced to spend an additional {{US$|9.5 million|link=yes}} to modify tracks to prevent derailments and the Type 8 fleet was unable to be used on the D branch (where cars reach full speed) after those modifications were complete in 2008.<ref name="netransit" />

As the final Type 8s were delivered, the last of the Boeing-Vertol cars were retired in March 2007 and all except ten of the cars were scrapped.<ref>{{cite news |url=http://www.boston.com/news/local/articles/2007/03/16/end_of_the_line_for_t_pioneers/ |newspaper=The Boston Globe |title=End of the line for T pioneers | date=March 16, 2007 |access-date=August 7, 2013}}</ref> Of the remaining cars, six were sold to the US Government and are now in [[Pueblo, Colorado]] for testing purposes, one was given to the [[Seashore Trolley Museum]], and three were retained by the MBTA for work service.

In 2006, as part of a [[MBTA accessibility#History|legal settlement]], the MBTA committed to always operate at least one low-floor car in each train, with no trains consisting only of Type 7 cars.<ref name=daniels />

Of the 120 Type 7 cars, 103 were overhauled by [[Alstom#Transport|Alstom]] in [[Hornell, New York]]. The work includes new propulsion systems, climate control systems and interiors as well as exterior work. The pilot car for the program left in October 2012 and was returned in November 2014, with the last car overhauled in April 2019.<ref>{{cite magazine |url=http://www.bostonmagazine.com/news/blog/2014/11/18/green-line-refurbished-trolley-sent-home/ |title=First of Refurbished Green Line Trolleys Heads Back Home |magazine=[[Boston (magazine)|Boston]] |date=November 18, 2014 |last=Annear |first=Steve |access-date=November 25, 2014 |archive-date=February 6, 2017 |archive-url=https://web.archive.org/web/20170206074047/http://www.bostonmagazine.com/news/blog/2014/11/18/green-line-refurbished-trolley-sent-home/ |url-status=dead }}</ref><ref name=roster />

=====Type 9=====
[[File:MBTA Green Line 3900 at Cleveland Circle station, February 2023.jpg|thumb|Type 9 LRV at Cleveland Circle in 2023]]

Twenty-four new Type 9 Green Line cars were delivered between 2017 and 2020. Revenue service began in late 2018 and all 24 cars were planned to enter service by the fall of 2019, although actual acceptance continued through 2021. The Type 9 cars will provide additional rolling stock to allow for [[Green Line Extension]] operations, and will not replace any of the existing fleet.<ref>{{Cite magazine |url=http://www.bostonmagazine.com/news/blog/2014/05/13/green-line-new-trains-could-happen-by-2017/ |title=New Green Line Trains Will Hit the Tracks by 2017 |author=Annear, Steve |magazine=[[Boston (magazine)|Boston]] |date=May 13, 2014 |access-date=May 20, 2014 |archive-date=July 13, 2017 |archive-url=https://web.archive.org/web/20170713182708/http://www.bostonmagazine.com/news/blog/2014/05/13/green-line-new-trains-could-happen-by-2017/ |url-status=dead }}</ref> The cars were made by [[Construcciones y Auxiliar de Ferrocarriles|CAF USA, Inc.]], with the shells and frames made in Spain, and final assembly and testing done at their plant in [[Elmira, New York]].<ref>{{cite web |url=http://www.railwaygazette.com/news/single-view/view/caf-wins-boston-green-line-order.html |title=CAF wins Boston Green Line order |work=Railway Gazette |date=May 16, 2014 |access-date=May 20, 2014 |archive-date=August 7, 2020 |archive-url=https://web.archive.org/web/20200807095952/https://www.railwaygazette.com/news/single-view/view/caf-wins-boston-green-line-order.html |url-status=dead }}</ref> {{As of|March 2017}}, the first unit had been expected to enter passenger service in Spring 2018, with all 24 cars in service by the end of the year.<ref>{{cite web |url=http://mbta.com/uploadedfiles/About_the_T/Board_Meetings/E.%20MBTA%20Type%209%20Board%20Update%20Mar%2020%202017%20Rev%2010%20w-notes-video.pdf |title=Green Line Type 9 Project Update |page=11 |publisher=Massachusetts Bay Transportation Authority |date=March 27, 2017 |access-date=March 29, 2017 |archive-date=March 29, 2017 |archive-url=https://web.archive.org/web/20170329233139/http://mbta.com/uploadedfiles/About_the_T/Board_Meetings/E.%20MBTA%20Type%209%20Board%20Update%20Mar%2020%202017%20Rev%2010%20w-notes-video.pdf |url-status=dead }}</ref> The first Type 9 car, #3900, began revenue service on December 21, 2018.<ref>{{Cite press release |url=https://www.mbta.com/news/2018-12-21/new-mbta-green-line-car-goes-passenger-service |title=New MBTA Green Line Car goes into Passenger Service |publisher=Massachusetts Bay Transportation Authority |date=December 21, 2018}}</ref>
{{Anchor|Type 10|Type 10 LRV}}

==== Future fleet ====
[[File:MBTA Green Line Type 10 mockup exterior 5.jpg|thumb|left|A full-scale mockup of the planned Type 10 "Supercar" LRV]]
Planning for a Type 10 fleet—which would replace all Type 7 and Type 8 cars in the mid-2020s—began in 2018 with plans for a fully [[Low-floor tram|low floor]] fleet.<ref name=":0">{{Cite web|date=7 May 2018|title=Green Line Transformation Program: Future Capacity Study Update - Fiscal & Management Control Board|url=https://cdn.mbta.com/sites/default/files/fmcb-meeting-docs/2018/may/2018-05-07-fmcb-green-line-future-capacity-without-appendicies.pdf|access-date=10 February 2021|website=[[MBTA]]}}</ref><ref name="SWAmay2020">{{cite web |url=https://cdn.mbta.com/sites/default/files/2020-05/2020-05-26-swa-initiatives-accessible.pdf |title=SWA Initiatives—May 2020 |date=May 26, 2020 |first=Laura |last=Brelsford |page=18}}</ref> At {{Convert|113|ft|m}} long, Type 10 cars would be significantly longer than the existing fleet, and carry twice as many passengers as existing cars.<ref name="spree">{{Cite web |last=Vaccaro |first=Adam |date=31 January 2020 |title=Next on the MBTA spending spree: bigger Green Line cars |url=https://www.bostonglobe.com/2020/01/31/metro/next-mbta-spending-spree-bigger-green-line-cars/ |archive-url= |archive-date= |access-date=2021-02-10 |website=[[Boston Globe]] |language=en-US}}</ref> The MBTA released a [[request for proposals]] in December 2019, with notice to proceed expected to be given in 2021. In June 2021, the MBTA indicated that the initial order would be for 102 LRVs operating as single cars, with two-car trains deferred for a later project with federal funding. Manufacturer bids were due in July 2021.<ref name=gltjune2021>{{cite web |url=https://cdn.mbta.com/sites/default/files/2021-06/2021-06-21-fmcb-15-green-line-transformation-update.pdf |title=Green Line Transformation (GLT) Update |date=June 21, 2021 |first=Angel |last=Peña |publisher=Massachusetts Bay Transportation Authority |page=9}}</ref>

The MBTA awarded an $811 million contract to [[Construcciones y Auxiliar de Ferrocarriles|CAF USA]] on August 31, 2022, to manufacture 102 seven-segment Type 10 "Supercar" LRVs. Four pilot vehicles are to be delivered in spring 2026, with deliveries of two LRVs per month from spring 2027 to spring 2031.<ref>{{cite web |url=https://cdn.mbta.com/sites/default/files/2022-08/RFP%20No%20367F-19%20Type%2010%20Supercar%20Update%20and%20Procurement%20AwardNP%20%28002%29.pdf |title=RFP No 367F-19 Type 10 Supercar Update and Procurement Award |first1=Angel |last1=Peña |first2=Bill |last2=Wolfgang |date=August 31, 2022 |publisher=Massachusetts Bay Transportation Authority}}</ref> The contract included options for additional LRVs.<ref name=swadec2022>{{cite web |url=https://cdn.mbta.com/sites/default/files/2022-12/2022-12-7-swa-initiatives-report-december-accessible.pdf |title=System-Wide Accessibility Initiatives—December 2022 |date=December 6, 2022 |publisher=Massachusetts Bay Transportation Authority Department of System-Wide Accessibility}}</ref> As a separately-funded project, [[Boston College station|Lake Street Yard]] will be fully reconstructed to support Type 10 vehicles, with Riverside Yard and the GLX Vehicle Maintenance Facility also modified.<ref>{{cite web |url=https://cdn.mbta.com/sites/default/files/2022-03/2022-03-24-proposed-fy23-27-mbta-cip-2.pdf |title=Massachusetts Bay Transportation Authority FY23-27 Capital Investment Plan (CIP): Proposed |date=March 2022 |publisher=Massachusetts Bay Transportation Authority |pages=66, 67}}</ref> When the Type 10 cars are delivered, the Type 9 fleet is expected to be transferred over to the [[Mattapan Line]], replacing the [[PCC streetcars]].<ref name="spree" />
{{clear}}

==Accessibility==
[[File:Longwood MBTA station, Brookline MA.jpg|thumb|A low-floor Type 8 car at Longwood station, which has slightly raised platforms for accessible boarding]]
<!--[[File:Mini-high platform at Newton Centre station, December 2015.JPG|thumb|right|Ramp at Newton Centre station to allow level boarding on older high-floor streetcars]]-->
{{See also|MBTA accessibility}}

The [[Red Line (MBTA)|Red Line]], [[Blue Line (MBTA)|Blue Line]], and [[Orange Line (MBTA)|Orange Line]] run [[rapid transit]] cars and use stations with [[railway platform height|high platforms]] level with the car floor providing easy access for the disabled. The Green Line originated as a [[tram|streetcar line]], and used a variety of streetcars before converting to light rail vehicles.

Originally all the Green Line stations had platforms at track level, and passengers had to ascend several steps up into the vehicles. This limited accessibility for persons with disabilities. To address this issue and comply with changing federal and state laws, additional facilities have been added:<ref>{{cite web|url=http://www.mbta.com/about_the_mbta/t_projects/projects_accessibility/|title=MBTA > About the MBTA > Transit Projects > Transit Projects and Accessibility<!-- Bot generated title -->|access-date=October 23, 2018|archive-url=https://web.archive.org/web/20120118122447/http://www.mbta.com/about_the_mbta/t_projects/projects_accessibility/|archive-date=January 18, 2012|url-status=dead}}</ref>

* Wheelchair lifts have been provided at some stops. They are rolled up to the car door and the lift mechanism is operated using a hand crank. They are quite time-consuming to operate, causing significant delays when used during peak periods.
* Short platforms level with car floors, accessed by ramps, were installed just before or after selected stations. Because the car door arrangement required a large gap between the platform and the car, a bridge plate attached to the raised platform had to be positioned after the train stopped with a door at that platform.
* The MBTA has followed the worldwide trend of operating [[low-floor tram|low-floor streetcars]]. Platforms are being raised slightly to about the height of a street curb. Low-floor cars have remotely controlled bridge plates at the center doors to allow wheelchairs and strollers to reach the car floor a few inches higher.{{citation needed|date=September 2022}} {{As of|2022}}, the D branch will be the first branch to be completely retrofitted with raised platforms as part of this program.<ref>{{cite web | title=MBTA reaches 75 percent design completion on Green Line D branch accessibility improvements project | website=Mass Transit Magazine | date=June 3, 2022 | url=https://www.masstransitmag.com/rail/infrastructure/press-release/21269932/massachusetts-bay-transportation-authority-mbta-mbta-reaches-75-percent-design-completion-on-green-line-d-branch-accessibility-improvements-project | access-date=September 26, 2022}}</ref>

==History==
{{see also|History of the MBTA|Boston-area streetcar lines}}

Beginning in the 1850s, Boston sprouted a large network of [[horsecar]] lines, the first public transit in the city. The [[West End Street Railway]] was created by the state legislature in 1887 to build a single line, but soon consolidated many of the existing lines into a single privately owned system with consistent fares and route designations. The Allston – Park Square line (which served the general area of the [[Green Line A branch|A branch]]) was the first section to be converted to [[electric traction]] in 1889. It used modified existing horsecars outfitted with [[Frank J. Sprague]]'s revolutionary electrical equipment, which had first been demonstrated the previous year in [[Richmond, Virginia]].<ref name=Cudahy>{{cite book|last1=Cudahy|first1=Brian J.|title=Change at Park Street Under; the story of Boston's subways|date=1972|publisher=S. Greene Press|location=Brattleboro, Vt.|isbn=0-8289-0173-2|url-access=registration|url=https://archive.org/details/changeatparkstre00cuda}}</ref>{{rp|9–10}} In 1897, the West End Street Railway property was handed over to the Boston Elevated Railway in the form of a 24-year lease, and the companies were ultimately combined.

By the early 1890s, the sheer quantity of streetcars during peak periods was clogging the streets of downtown Boston. The Tremont Street subway, the first passenger subway in North America, was opened in stages in 1897 and 1898, with underground stations at [[Boylston (MBTA station)|Boylston]], Park Street, [[Government Center (MBTA station)|Scollay Square]], [[Adams Square (BERy station)|Adams Square]], and [[Haymarket (MBTA station)|Haymarket]]. The [[Orange Line (MBTA)|Main Line Elevated]] was run through the tunnel from 1901, displacing through-running streetcars,<ref name="Cudahy"/>{{rp|19–21}} until it was rerouted to its own [[Washington Street Tunnel (Boston)|Washington Street Tunnel]] in 1908, and the streetcars were returned to the Tremont tunnel.<ref name="Cudahy"/>{{rp|27}}

Though initially intended merely to clear streetcars from the busiest sections of downtown streets, the Tremont Street subway became useful as a rapid transit service in its own right. The 1912 completion of the [[Causeway Street Elevated]] and [[Lechmere Viaduct]] extended grade-separated service to [[Lechmere Square]] in Cambridge, and in 1922 the [[Lechmere (MBTA station)|Lechmere transfer station]] was built.  In 1914, the Boylston Street subway opened as a westward extension to just short of [[Kenmore Square]], and in 1933 [[Kenmore (MBTA station)|Kenmore station]] and short tunnel extensions towards two surface lines were added. In 1941, the [[Huntington Avenue subway]] and its two additional underground stations removed the last surface streetcars from downtown Boston.

Beginning in the 1930s, the [[Boston-area streetcar lines|massive surface streetcar system]] was "[[bustitution|bustituted]]" with buses and [[Trolleybuses in Greater Boston|trackless trolleys]] which had lower operating costs and more flexible routes. As the 1950s closed out, the only remaining streetcar lines were the [[Green Line A branch|Watertown Line]], [[Green Line B branch|Commonwealth Avenue Line]], [[Green Line C branch|Beacon Street Line]], [[Green Line E branch|Arborway Line]], and the [[43 (MBTA bus)|Lenox Street Line]] plus several [[short turn]] services. In 1959, the [[Boston and Albany Railroad]]'s Highland Branch was converted to the [[Green Line D branch|Riverside Line]], a fully grade-separated suburban service.  In 1961, the last through service to Lenox Street via the [[Pleasant Street portal]] ended, though a Pleasant Street – Boylston shuttle continued for one more year. In 1963, part of the original subway was rebuilt under [[Government Center (Boston)|Government Center]], abandoning and partially demolishing Adams Square station.

In 1947, the now-bankrupt BERy was replaced by the public [[Metropolitan Transit Authority (Boston)|Metropolitan Transit Authority]] (M.T.A.). The new agency was unpopular, even spawning [[M.T.A. (song)|a popular protest song]]; in 1964, it was replaced with the [[Massachusetts Bay Transportation Authority]] which had an expanded funding area to preserve suburban commuter rail lines. In 1967, as part of a systemwide rebranding that included new station names and color names for the transit lines, the remaining streetcar services were designated the "Green Line" because several of them traveled near the [[Emerald Necklace]] park system. The streetcar lines were given letter designations: "A" to the Watertown Line, "B" to the Commonwealth Avenue Line, "C" to the Beacon Street Line, "D" to the Riverside Line, and "E" to the Arborway Line.

The Watertown Line ran mostly in [[street running|mixed traffic]] after diverging from Commonwealth Avenue; it was permanently replaced with buses in 1969. The section of the Arborway Line past [[Heath Street (MBTA station)|Heath Street]] was "temporarily" – ultimately permanently – bustituted in 1985. In 2001, with new low-floor streetcars entering service, the MBTA began retrofitting underground stations and major surface stops with low raised platforms for accessibility for all. In 2004, the Causeway Street Elevated was replaced with a new tunnel under the [[Boston Garden]], which consolidated the Orange Line and Green Line at a new [[North Station (subway)|North Station]] "superstation", while continuing to connect to Commuter Rail service north of Boston.

The name "Green Line" was assigned in 1967 as part of a major reorganization of the MBTA system's branding.<ref name=netransit /> In the 1970s, the Green Line and all other MBTA lines were re-evaluated by the [[BTPR|Boston Transportation Planning Review]] for region-wide efficacy and future modernization alternatives initiated as far as physical plant and operating measures.

==Operations and signaling==
[[File:Green Line wayside signals near Newton Highlands.jpg|thumb|right|Trains on the D branch operate using wayside signals.]]
{{As of|February 2023}}, each of the four branches operate on 7- to 9-minute headways during weekday peak hours, and 8- to 12-minute headways at other times. Vehicle usage ranges from 45 trains (90 cars) to 62 trains (124 cars).<ref>{{cite magazine |magazine=Rollsign |publisher=[[Boston Street Railway Association]] |date=January–February 2023 |issue=1–2 |volume=60 |title=MBTA Vehicle Inventory as of February 28, 2023 |first=Jonathan |last=Belcher |page=10}}</ref>

Unlike the MBTA's heavy rail subway lines, the Green Line has only limited central control and monitoring. This also means that it has lagged behind the other three rail lines in the availability of countdown signs and "next train" arrival information. The line is signalled with advisory [[Railway signalling|wayside signals]], except on surface portions in street medians or [[street-running|in-street running]]. Wayside signal territory stretches from Lechmere to the surface portals at Kenmore, and along the entire length of the D–Riverside branch. There are no [[Train protection system|automatic protection devices]], but the cars have [[Electromagnetic track brake|track brakes]], giving the ability to stop quickly under control of the operator. Interlockings are controlled through a wayside Automatic Vehicle Identification (AVI) system that relies on the operator properly entering the destination manually on a roto-wheel in the train cab at the beginning of a run.

The line is monitored from the [[Operations control center|Operations Control Center]] (OCC). Responsibility for controlling service is shared by the control room and field personnel along the right of way. Track circuit and signal indications are not transmitted to the operational personnel sites. In lieu of track circuit indications, the AVI system is displayed in the control room to provide a periodic update to train position wherever AVI detectors exist. The AVI system user interface was solely text based until the current control room was opened, in which a new schematic display based on AVI data was instituted. Track circuit indications are available digitally in signal houses at the Park Street interlocking, at the new North Station interlocking, and at the new Kenmore interlocking, but are not transmitted to OCC. In January 2013, the MBTA announced plans to add full vehicle location tracking on the Green Line for countdown signs and smartphone applications, including using AVI data in the tunnels and GPS receivers on the surface lines.<ref name=trackingstory /> The first real-time data—location data on the surface lines—became available in October 2014. Full tracking was expected by early 2015.<ref name=aboveground />

The MBTA typically runs two-car trains at all times. The last scheduled use of one-car trains on weekdays was in March 2007.<ref name=netransit /> Three-car trains were added on the B and D branches in 2010 – their first use since 2005 – and a four-car train was tested in April 2011.<ref name=netransit /> In March 2011, the number of three-car trains was substantially increased, including use on the E branch.<ref name=netransit /><ref>{{cite press release |url=https://www.mbta.com/news/2011-03-16/green-line-nearly-triple-the-number-3-car-trains |title=Green Line to nearly triple the number of 3-car trains |date=March 16, 2011 |publisher=Massachusetts Bay Transportation Authority}}</ref> However, three-car trains suffered from reliability problems and slow boarding.<ref>{{cite news |url=https://www.boston.com/news/local-news/2016/05/03/mbta-green-line-crowded|title=Why is the Green Line so crowded? |date=May 3, 2016 |newspaper=Boston Globe |first=Adam |last=Vaccaro}}</ref> The use of three-car trains ended in March 2016.<ref name=netransit />

=== Positive train control ===
The MBTA approved an $82.6 million contract in May 2019 for a [[positive train control|train protection system]] for the Green Line. The system would enforce red signals and automatically stop a train if it approached another train too closely.<ref>{{cite web |url=https://cdn.mbta.com/sites/default/files/fmcb-meeting-docs/2019/05-may/2019-05-20/2019-05-20-fmcb-joint-26-green-line-train-protection-system.pdf |title=Green Line Train Protection System (GLTPS) System Integration Contract |date=May 20, 2019 |publisher=Massachusetts Bay Transportation Authority}}</ref> The project was 28% complete by December 2021; installation of in-vehicle electronics was scheduled to be complete by September 2023, with wayside installation complete in June 2024 and full operation that December.<ref>{{cite web |url=https://cdn.mbta.com/sites/default/files/2021-12/2021-12-15-GLTPS-report-accessible.pdf |title=GLTPS Monthly Review and Lookahead |date=December 15, 2021 |publisher=Massachusetts Bay Transportation Authority}}</ref> A reallocation of funds in January 2022 shortened the project timeline, with completion expected in 2023.<ref>{{cite press release |url=https://www.mbta.com/projects/green-line-train-protection-system/update/new-funding-accelerates-green-line-train |title=New Funding Accelerates Green Line Train Protection System Project Timeline |date=February 25, 2022 |publisher=Massachusetts Bay Transportation Authority}}</ref> However, in January 2023, an NTSB report found that the project had been delayed to June 2025.<ref>{{cite news |url=https://www.bostonglobe.com/2023/01/05/metro/green-line-crash-would-have-been-prevented-if-mbta-had-installed-train-tech-earlier-ntsb-finds/ |title=Green Line crash "would have been prevented" if MBTA had installed train tech earlier, NTSB finds |first=Taylor |last=Dolven |date=January 5, 2023 |newspaper=Boston Globe |archive-url=https://web.archive.org/web/20230105235222/https://www.bostonglobe.com/2023/01/05/metro/green-line-crash-would-have-been-prevented-if-mbta-had-installed-train-tech-earlier-ntsb-finds/ |archive-date=January 5, 2023}}</ref> The MBTA cancelled the contract in June 2024 citing a lack of progress and an inability by the contractor to complete the project.<ref name="GLTPS scrapped">{{cite news |archive-url=https://web.archive.org/web/20240607210038/https://www.bostonglobe.com/2024/06/07/metro/green-line-crash-prevention-tech/ |archive-date=June 7, 2024 |date=June 7, 2024 |title=T scraps Green Line crash-prevention contract recommended by NTSB in 2009 |url=https://www.bostonglobe.com/2024/06/07/metro/green-line-crash-prevention-tech/ |first=Taylor |last=Dolven |newspaper=The Boston Globe}}</ref>

The MBTA worked with a different contractor to develop the GLTPS-2 system in two phases. Phase 1, expected to be installed on the existing Type 7, Type 8, and Type 9 fleet by the end of 2025, will be an operator warning system with alarms that trigger when a train is exceeding speed limits or is at risk of imminent collision with another train. Phase 2, which will be installed only on the Type 9 and future Type 10 fleet, adds automatic enforcement by braking and is planned to be finished by June 2028. A $112.5 million contract to install the system was approved in February 2025.<ref name="boardmeeting20250225">{{cite web |url=https://cdn.mbta.com/sites/default/files/2025-02/5.%20GLTPS-2%20Staff%20Summary%20Presentation%202-24-2025%20FINAL_2PM.pdf |date=February 25, 2025 |publisher=Massachusetts Bay Transportation Authority |title=Green Line Train Protection System (GLTPS-2) Procurement |first1=William G. |last1=Wolfgang |first2=Raymond F. |last2=Wise}}</ref>

===Turnarounds===
[[File:D train on Kenmore Loop October 2024.jpg|thumb|right|A D branch train on the loop at Kenmore station in 2024]]
Aside from the terminal stations, several locations have [[balloon loop|turnaround loop]]s or [[Crossover (rail)|crossover switches]] where trains can reverse direction for [[short turn]]s. One of these, where northbound trains can turn southbound, is regularly used as the downtown terminal for two of the branches:

* At {{bts|Government Center}}, a loop under [[City Hall Plaza (Boston)|City Hall Plaza]]. {{As of|2022}}, this is the terminal of the B and C branches.

Several other loops and crossovers are not used in regular revenue service but may be used during construction work or service disruptions, or for non-revenue trains, with some having been regularly used as terminals in the past:<ref name=bluebook /><ref name=netransit />
* At {{bts|North Station|Green}}, a pair of [[pocket track]]s allow reversing.
* At Government Center, the [[Government Center station (MBTA)#Scollay Square|Brattle Loop]] allows southbound trains to turn northbound, however, this loop is currently only used during service disruptions.
* At {{bts|Park Street}}, a loop connects the inner tracks. The MBTA plans to add a crossover to allow through movements from the terminating (inner) northbound platform at Park Street are expected to increase capacity and reliability.<ref>{{cite web|title=MBTA Capital Investment Program FY15-FY19|url=http://www.mbta.com/uploadedfiles/About_the_T/Financials/FINAL%20FY15-19%20MBTA%20Capital%20Investment%20Program.pdf|publisher=MBTA|access-date=April 23, 2015|page=124|date=March 12, 2014|archive-date=July 25, 2014|archive-url=https://web.archive.org/web/20140725132040/http://mbta.com/uploadedfiles/About_the_T/Financials/FINAL%20FY15-19%20MBTA%20Capital%20Investment%20Program.pdf|url-status=dead}}</ref>
* At {{bts|Kenmore}}, a loop allows eastbound (inbound) C and D branch trains to turn westbound.
* On the B branch, a pocket track at {{bts|Blandford Street}} allows trains to reverse in either direction. It is sometimes used to reverse westbound trains to provide extra service in the subway. Occasionally-used crossovers are located at {{bts|Babcock Street}}, {{bts|Washington Street}}, and east of {{bts|Boston College}}.
* On the C branch, occasionally-used crossovers are located at {{bts|Saint Marys Street|C}} and {{bts|Coolidge Corner}}.
* On the D branch, occasionally-used crossovers are located west of {{bts|Fenway}}, {{bts|Brookline Hills}}, {{bts|Beaconsfield}}, {{bts|Reservoir}}, {{bts|Newton Highlands}}, and {{bts|Waban}}. At Reservoir, the spur tracks to Reservoir Carhouse have platforms for short turn trains.
* On the E branch, crossovers are located at {{bts|Prudential}}, {{bts|Northeastern University}}, and {{bts|Brigham Circle}}, along with a siding at Northeastern. The Brigham Circle crossover is frequently used for short turns during traffic congestion on the street-running section of the line.

===Location tracking===
[[File:Activated countdown signs at Kenmore station, August 2015.JPG|thumb|left|Activated countdown signs at Kenmore station in August 2015]]
The Red, Orange, and Blue lines have block signalling systems that make tracking the location of trains easier. Signs in most station on those lines began to display real-time train information in late 2012 and early 2013, while data feeds have been available for smartphone applications since 2010.<ref name=trackingstory>{{cite news |url=http://www.boston.com/yourtown/news/allston_brighton/2013/01/mbta_mobile_apps_will_be_able.html |title=MBTA: Mobile apps will be able to track Green Line trains by 2015 |author=Rocheleau, Matt |date=January 22, 2013 |newspaper=Boston Globe |access-date=January 22, 2013}}</ref> However, the wayside signalling system used in the Green Line's tunnels and the D branch does not provide for that level of tracking, nor do the basic stop/go signals used on the street-level branch lines. In January 2013, the MBTA announced plans to provide full tracking data for the Green Line by 2015, allowing use of smartphone applications and in-station countdown signs.<ref name=trackingstory /> The $13.4&nbsp;million<!--15 million in early stories--> system is funded by MassDOT; it uses existing Automatic Vehicle Identification (AVI) systems plus additional sensors in the tunnels, and GPS receivers on the surface sections.<ref name=march2015 />

In September 2013, the MBTA announced that "Next Train" signs would be unveiled at [[Kenmore (MBTA station)|Kenmore]] that month.<ref>{{cite news |url=http://www.bostonmagazine.com/news/blog/2013/09/18/green-line-next-train-signs/ |title=The MBTA's Green Line Is Getting 'Next Train' Electronic Information Boards |newspaper=Boston Magazine |date=September 18, 2013 |author=Annear, Steve |access-date=September 18, 2013 |archive-date=April 8, 2016 |archive-url=https://web.archive.org/web/20160408142736/http://www.bostonmagazine.com/news/blog/2013/09/18/green-line-next-train-signs/ |url-status=dead }}</ref> On October 23, 2014, location tracking data became available for Green Line trains above ground. Arrival predictions for surface stations – including the activation of countdown signs along the [[Green Line D branch|D branch]] – and underground tracking and predictions were to be rolled out in two phases by early 2015.<ref name=aboveground>{{cite press release |url=http://www.mbta.com/about_the_mbta/news_events/?id=6442453268&month=&year= |title=CUSTOMERS ARE NOW ABLE TO TRACK GREEN LINE TRAINS |publisher=Massachusetts Bay Transportation Authority |date=October 23, 2014 |access-date=October 28, 2014}}</ref> In March 2015, the MBTA announced that enough AVI equipment had been installed to allow the release of some underground data by April.<ref name=march2015>{{cite press release |url=http://www.mbta.com/about_the_mbta/news_events/?id=6442453903&month=&year= |title=MBTA installing underground tracking system for Green Line trolleys |publisher=Massachusetts Bay Transportation Authority |date=March 3, 2015 |access-date=March 12, 2015}}</ref> Most underground data was live by August, but trains near Park Street and Boylston waited until September.

The first predictive countdown signs on the Green Line were activated at [[Newton Centre (MBTA station)|Newton Centre]] and [[Newton Highlands (MBTA station)|Newton Highlands]] on April 24, 2015, followed shortly by other D branch stations.<ref>{{cite press release |url=http://www.mbta.com/about_the_mbta/news_events/?id=6442454218&month=&year= |title=Green Line's First Countdown Signs Go Live in Newton |publisher=Massachusetts Bay Transportation Authority |date=April 24, 2015 |access-date=April 25, 2015}}</ref> Countdown signs at Kenmore and Hynes were activated in August 2015. Signs at Copley and Arlington plus eastbound-only signs from Boylston through Science Park were activated in October 2015.<ref>{{cite news |url=https://www.bostonglobe.com/metro/2015/10/06/green-line-get-countdown-clocks-downtown-stations/QPDZaPM0g9zVL2NrQiTJYP/story.html |title=Green Line to get countdown clocks in downtown stations |newspaper=Boston Globe |last=Roberts |first=Sarah |date=October 6, 2015 |access-date=October 6, 2015}}</ref> The final set of signs – those on the westbound platforms of Science Park through Boylston – were activated in January 2016. Because holding and short-turning trains at the downtown terminals makes time-based predictions unreliable, the signs instead show how many stops away a train is.<ref>{{cite news |url=http://www.boston.com/news/local/massachusetts/2016/01/20/why-the-green-line-new-countdown-clocks-measure-stops-away-instead-time/679eCMzAUmcUKN3hSGYuFK/story.html |title=Why the Green Line's new countdown clocks measure 'stops away' instead of time |newspaper=Boston Globe |date=January 20, 2016 |last=Levenson |first=Eric |access-date=January 20, 2016}}</ref>

==Projects==
===Somerville/Medford extension===
[[File:Green Line Extension.svg|thumb|left|upright=1.25|Map of the Green Line Extension. Nearby parts of the Red Line and Orange Line are also shown.]]
The [[Green Line Extension]] (GLX) project added two new branches into the northern suburbs of [[Somerville, Massachusetts|Somerville]] and [[Medford, Massachusetts|Medford]]. The project opened in two phases in 2022 at a total cost of $2.28 billion. The rebuilt [[Lechmere station]] and the Union Square Branch to {{bts|Union Square|Green|E}} opened on March 21, 2022, as an extension of the D branch (briefly the E branch). The Medford Branch opened to {{bts|Medford/Tufts}} on December 12, 2022, as an extension of the E branch, with intermediate stations at {{bts|East Somerville}}, {{bts|Gilman Square}}, {{bts|Magoun Square}}, and {{bts|Ball Square}}.<ref name="mar21">{{cite press release |last1=MacCormack |first1=Terry |title=Baker-Polito Administration Celebrates Opening of the Green Line Extension |url=https://www.mass.gov/news/baker-polito-administration-celebrates-opening-of-the-green-line-extension |publisher=[[Government of Massachusetts]] |date=March 21, 2022 |access-date=December 13, 2022 |archive-date=December 4, 2022 |archive-url=https://web.archive.org/web/20221204085822/https://www.mass.gov/news/baker-polito-administration-celebrates-opening-of-the-green-line-extension |url-status=dead }}</ref><ref name="dec12">{{cite press release |url=https://www.mbta.com/news/2022-12-12/mbta-celebrates-opening-the-green-line-extension-medford-branch |publisher=[[Massachusetts Bay Transportation Authority]] |title=MBTA Celebrates Opening of the Green Line Extension Medford Branch |date=December 12, 2022}}</ref> The total project cost is estimated to be $2.28 billion: $0.996 billion from the federal government and $1.28 billion from the state. Daily ridership on the extension is projected to be 45,000 by 2030.<ref>{{cite web |url=https://www.mass.gov/info-details/about-the-green-line-extension-project |title=About the Green Line Extension Project |publisher=Massachusetts Department of Transportation |access-date=September 28, 2020}}</ref>

The GLX begins at the north end of the [[Lechmere Viaduct]], with a new elevated line continuing north for about {{convert|0.6|miles}} parallel to the [[Massachusetts Route 28|O'Brien Highway]]. The former surface-level Lechmere station was replaced by an elevated station on the new alignment. The two branches split with an aerial [[flying junction]] on the Red Bridge viaduct in the [[Inner Belt (Somerville)|Inner Belt]] area. The Union Square Branch runs {{convert|0.7|miles}} west from Red Bridge, sharing the [[Fitchburg Line]] right of way. The Medford Branch runs {{convert|3.0|miles}} northwest from Red Bridge, sharing the [[Lowell Line]] right of way. Like the existing D branch, the new branches are fully grade-separated, with no [[level crossing]]s. A new vehicle storage yard and maintenance facility is located in the Inner Belt area, with leads from both branches at Red Bridge. An extension of the [[Somerville Community Path]] runs along the Medford Branch south of Lowell Street, with a high bridge carrying it above the Red Bridge viaduct.

An extension north from Lechmere was first proposed in the 1920s, and again several times during the 20th century. To settle a lawsuit with the [[Conservation Law Foundation]] to mitigate increased automobile emissions from the [[Big Dig]], the Commonwealth of Massachusetts agreed in 1990 to extend the Green Line from Lechmere to Medford Hillside through Somerville and Medford, two suburbs underserved by the MBTA relative to their population densities, commercial importance, and proximity to Boston. After delays in planning, the state agreed in 2006 to complete the project by 2014.<ref>{{cite news|last=Cummings|first=Claire|date=August 9, 2007|title=Proponents rap delay to extend Green Line|newspaper=[[The Boston Globe]]|url=https://www.boston.com/news/local/articles/2007/08/09/proponents_rap_delay_to_extend_green_line/|access-date=August 26, 2007}}</ref> The preferred alternative from the 2009  Draft Environmental Impact Report added the Union Square Branch; the Medford Branch terminus was set as College Avenue, with a potential future extension to {{bts|Mystic Valley Parkway}}.

The planned completion was delayed to 2018 in 2011, and to 2020 in 2014.<ref name=Green2018>{{cite news|last=Byrne|first=Matt|title=State: Green Line extension will be delayed til 2018|url=http://www.boston.com/yourtown/news/medford/2011/08/state_greenline_extension_will.html|access-date=August 1, 2011|newspaper=boston.com (The Boston Globe)|date=August 1, 2011}}</ref><ref>{{cite web|last=Metzger |first=Andy |url=http://www.wbur.org/2014/09/13/green-line-extension-cost-rises-to-2-billion |title=Green Line Extension Cost Rises To $2 Billion |date=September 13, 2014 |publisher=WBUR |access-date=February 10, 2015}}</ref> A groundbreaking ceremony was held in December 2012.<ref>{{cite web |url=http://transportation.blog.state.ma.us/blog/2012/12/green-line-extension-phase-1-construction-begins.html |title=Green Line Extension Phase 1 Construction Begins |date=December 11, 2012 |publisher=Massachusetts Department of Transportation |work=Commonwealth Conversation: Transportation |access-date=December 15, 2012 |archive-date=June 22, 2013 |archive-url=https://web.archive.org/web/20130622145547/http://transportation.blog.state.ma.us/blog/2012/12/green-line-extension-phase-1-construction-begins.html |url-status=dead }}</ref> The project was expected to cost about $2.2 billion, with half of that paid by the [[Federal Transit Administration]] (FTA). However, in 2015 it became clear that the project would cost $3 billion, putting its future in doubt.<ref>{{cite web |url=http://www.boston.com/news/local/massachusetts/2015/12/14/transit-officials-won-commit-more-state-money-green-line-extension/oUrryP4kQA2x4d52X7PaIP/story.html |title=Transit officials won't commit additional state money to Green Line extension |newspaper=Boston Globe |date=December 14, 2015 |last=Vaccaro |first=Adam |access-date=December 15, 2015}}</ref> The project was [[Value engineering|value engineered]] to reduce its cost: station designs were simplified, several bridge reconstructions eliminated, the Community Path extension shortened, and the maintenance facility reduced in size.<ref>[http://mbta.com/uploadedfiles/About_the_T/Board_Meetings/GLXBOARDREPORTFINALv2.pdf Interim Project Management Team Report: Green Line Extension Project{{snd}}Report to the MBTA Fiscal and Management Control Board and the MassDOT Board of Directors] {{Webarchive|url=https://web.archive.org/web/20170829002946/http://mbta.com/uploadedfiles/About_the_T/Board_Meetings/GLXBOARDREPORTFINALv2.pdf |date=August 29, 2017 }} Submitted May 9, 2016</ref><ref>{{cite news|title=Somerville's getting a brand new bike path with the Green Line extension. Is it wide enough?|first=Adam|last= Vaccaro|publisher=The Boston Globe|date= May 13, 2019|url=https://www.bostonglobe.com/metro/2019/05/13/somerville-getting-brand-new-bike-path-with-green-line-extension-wide-enough/yN9ryYa2fDyZDWQGcO40PJ/story.html}}</ref> The FTA approved the modified $2.3 billion plan on April 4, 2017.<ref name=globe417>{{cite news |url=https://www.bostonglobe.com/metro/2017/04/04/feds-green-line-extension-costs-securing-project-future/6Nsiskpk14qQO43vBl9H1I/story.html |title=Feds OK Green Line extension costs, securing project's future |newspaper=Boston Globe |date=April 4, 2017 |first=Nicole |last=Dungca |access-date=April 4, 2017}}</ref> The contract was rebid with a provision for the optional restoration of six of the elements deleted in the 2016 plan. The winning bid, selected in November 2017, included six optional elements, including canopies and additional elevators at stations, public art, a full-size vehicle maintenance facility, and the full extension of the Community Path to East Cambridge.<ref name=selected>{{cite press release |url=http://blog.mass.gov/transportation/mbta/green-line-extension-project-design-build-team-firm-selected/ |title=Green Line Extension Project Design-Build Team Firm Selected |publisher=Massachusetts Department of Transportation |date=November 17, 2017 |first=Klark |last=Jessen |access-date=June 22, 2021 |archive-date=January 28, 2022 |archive-url=https://web.archive.org/web/20220128223614/http://blog.mass.gov/transportation/mbta/green-line-extension-project-design-build-team-firm-selected/ |url-status=dead }}</ref><ref>{{Cite news|url=https://www.bostonglobe.com/metro/2017/11/17/green-line-extension-expects-green-light-from-mbta-friday/PjN5cg0CHi5dsYC4IFY3sL/story.html|title=MBTA chooses winning bidder for Green Line extension and awards its biggest contract ever |work=Boston Globe|access-date=2017-11-22|archive-date=April 6, 2019|archive-url=https://web.archive.org/web/20190406213638/https://www.bostonglobe.com/metro/2017/11/17/green-line-extension-expects-green-light-from-mbta-friday/PjN5cg0CHi5dsYC4IFY3sL/story.html|url-status=dead}}</ref> Construction reached 20% completion in November 2019; it was over 50% completed by October 2020, and 80% by June 2021.<ref>{{cite news |url=https://www.wcvb.com/article/construction-on-green-line-extension-20-percent-complete/29811265 |title=Construction on Green Line extension 20 percent complete |newspaper=WCVB |date=November 15, 2019 |first=Katie |last=Thompson}}</ref><ref>{{cite press release |url=https://www.mbta.com/news/2020-10-01/baker-polito-administration-transportation-officials-visit-green-line-extension |title=Baker-Polito Administration, Transportation Officials Visit Green Line Extension Project |date=October 1, 2020 |publisher=Massachusetts Bay Transportation Authority}}</ref><ref name=june2021>{{cite web |url=https://cdn.mbta.com/sites/default/files/2021-06/2021-06-21-fmcb-14-green-line-extension-update.pdf |page=19 |title=Green Line Extension Update |first=John |last=Dalton |date=June 21, 2021 |publisher=Massachusetts Bay Transportation Authority}}</ref>

{{anchor|Light Rail Accessibility Program}}

===Accessibility renovations===
[[File:Government Center construction, September 2014.jpg|thumb|right|Government Center station under reconstruction in September 2014]]
The majority of the Green Line opened by 1959, long before the 1990 [[Americans with Disabilities Act]] mandated that new construction be fully [[accessible]]. The MBTA began modifying Red, Orange, and Blue Line stations for accessibility in the late 1980s; however, Green Line stations were not modified until the late 1990s, when the Type 8 vehicles were under construction. The MBTA began the Light Rail Accessibility Program in 1996.<ref name=audit>{{cite report |title=Official Audit Report – Issued June 16, 2014: Massachusetts Bay Transportation Authority, For the period January 1, 2005 through December 31, 2012 |date=June 16, 2014 |url=https://www.mass.gov/files/documents/2016/08/ww/201305833a.pdf |publisher=Auditor of the Commonwealth}}</ref>{{rp|30}} Because modifying the numerous stations all at once would be prohibitively expensive, the MBTA designated "key stations" – largely those with high ridership or bus connections – for prioritization.<ref name=PMTaccess>{{cite web |archive-url=https://web.archive.org/web/20120220063458/http://www.bostonmpo.org/bostonmpo/pmt-old/PMT-1.pdf |archive-date=February 20, 2012 |url=http://www.bostonmpo.org/bostonmpo/pmt-old/PMT-1.pdf |title=Executive Summary |work=Program of Mass Transportation |date=January 2004 |publisher=Boston Regional Metropolitan Planning Organization |pages=2–9}}</ref>

Riverside station was completely rebuilt with raised accessible platforms around 1998. {{bts|North Station|Green}} and {{bts|Park Street}} (both of which already had elevators from previous projects) were outfitted with [[wheelchair lift|portable lift]]s for temporary accessibility around 2000, as were {{bts|Lechmere}} and ten surface stations.<ref name=PMTaccess /> Between 2001 and 2003, 16 surface stations (4 on the B branch, 4 on the C branch, 3 on the D branch, and 5 on the E branch)<!--Riverside already done, Brookline Hills never modified, and BV and BC not modified until 2009)--> were retrofitted with raised platforms.<ref name=bluebook2003>{{cite book |url=https://archive.org/details/ridershipservice2003mass/page/n45 |page=2.19 |title=Ridership & Service Statistics |date=2004 |edition=9 |publisher=Massachusetts Bay Transportation Authority |via=Internet Archive}}</ref> The 13 B, C, and E branch stations collectively cost $32&nbsp;million.<ref>{{cite web |archive-url=https://web.archive.org/web/20040810020602/http://www.mbta.com/insidethet/3_GreenLine.asp |archive-date=August 10, 2004 |url=http://www.mbta.com/insidethet/3_GreenLine.asp |title=Planned Accessibility Projects – On Board the Green Line |publisher=Massachusetts Bay Transportation Authority}}</ref> Construction of raised platforms was completed at Park Street and Haymarket around 2003; Prudential was also reconstructed that year by the developer of [[111 Huntington Avenue]]. The fully accessible underground "superstation" at North Station opened in 2004.<ref name=netransit /> Wooden [[Railway platform height#mini-high|mini-high platforms]], allowing level boarding on older Type 7 LRVs, were installed at eight Green Line stations in 2006–07 as part of the settlement of ''[[MBTA accessibility#History|Joanne Daniels-Finegold, et al. v. MBTA]]''.<!-- Coolidge and Wash Sq were never built; BC, Heath, and Lechmere were earlier--><ref name=daniels>{{cite web |url=http://www.gbls.org/sites/default/files/settlement-(4-10-06).pdf |title=Settlement Agreement |work=Joanne Daniels-Finegold et al. v. MBTA |date=April 10, 2006 |pages=10–11}}</ref><ref>{{cite web |url=http://ctps.org/bostonmpo/4_resources/2_transreport/archive/trpt0607.pdf |archive-url=https://web.archive.org/web/20110116153104/http://ctps.org/bostonmpo/4_resources/2_transreport/archive/trpt0607.pdf |title=Green Line Stations Upgraded to Improve Accessibility |date=June 2007 |work=TRANSReport |publisher=Boston Regional Metropolitan Planning Organization |archive-date=January 16, 2011}}</ref>

Renovations for accessibility were completed at {{bts|Arlington}} in 2009,<ref>{{cite news |url=http://www.boston.com/news/local/massachusetts/articles/2009/06/02/back_bay_t_station_reopens_with_improved_access_for_disabled_riders/ |title=Arlington T station reopens with disabled access |newspaper=Boston Globe |author=Bierman, Noah |date=June 2, 2009 |access-date=May 23, 2012}}</ref> {{bts|Kenmore}} and {{bts|Copley}} in 2010,<ref>{{cite news |url=http://www.boston.com/yourtown/news/back_bay/2010/09/copley_station_project_nears_e.html |title=Copley station project nears end; historic church plans repairs |author=Rocheleau, Matt |date=September 14, 2010 |newspaper=Boston Globe |access-date=May 23, 2012}}</ref><ref>{{cite news |url=https://www.newspapers.com/clip/37722088/the_boston_globe/ |title=Kenmore station upgrades done, finally |date=April 25, 2010 |page=B2 |newspaper=Boston Globe |first=Eric |last=Moskowitz |via=Newspapers.com}}{{open access}}</ref> and {{bts|Science Park}} in 2011.<ref>{{cite news |url=http://articles.boston.com/2011-11-03/news/30355635_1_trolley-service-science-park-project-ends |title=Trolley service to resume as project end |newspaper=Boston Globe |date=November 3, 2011 |access-date=May 23, 2012 |archive-date=May 31, 2012 |archive-url=https://web.archive.org/web/20120531181757/http://articles.boston.com/2011-11-03/news/30355635_1_trolley-service-science-park-project-ends |url-status=dead }}</ref> A two-year closure of {{bts|Government Center}} ended in 2016 with the opening of the accessible transfer station.<ref>{{cite news |url=https://www.bostonglobe.com/metro/2016/03/21/government-center-station-reopens/roZebAYCCykVGWPw7vVAeO/story.html |title=Government Center reopens |newspaper=Boston Globe |date=March 21, 2016 |first=Eric |last=Moskowitz |access-date=March 21, 2016}}</ref> As part of the Green Line Extension, Lechmere was replaced by a fully accessible elevated station in 2022.<ref name=SWAJune2024 /> Reconstruction work on Symphony is expected to take place from 2025 to 2028.<ref name=SWADec2024>{{cite web |url=https://cdn.mbta.com/sites/default/files/2024-12/2024-12-06-accessibility-initiatives.pdf |title=Accessibility Initiatives—December 2024 |date=December 6, 2024 |publisher=Massachusetts Bay Transportation Authority |pages=3–6}}</ref> {{bts|Hynes Convention Center}} (with renovations in design) and {{bts|Boylston}} are the other remaining inaccessible stations in the central subway.<ref name=SWAJune2024>{{cite web |url=https://cdn.mbta.com/sites/default/files/2024-06/2024-06-Accessibility-Initiatives.pdf |title=Accessibility Initiatives—June 2024 |date=June 25, 2024 |publisher=Massachusetts Bay Transportation Authority |pages=2–5}}</ref>

Other projects have moved towards full accessibility of the surface branches. {{bts|Woodland}} was made accessible in 2006.<ref>{{cite journal |url=http://archives.lib.state.ma.us/bitstream/handle/2452/37426/ocm10561343-2006-04.pdf?sequence=1 |title=MPO Agency Notes |publisher=Boston Region Metropolitan Planning Organization |journal=TRANSreport |date=April 2006 |via=Internet Archive}}</ref> Renovations completed in 2009 made {{bts|Longwood}} accessible for the first time, and replaced the lifts at {{bts|Boston College}} and {{bts|Brookline Village}}.<ref>{{cite news |url=http://www.boston.com/yourtown/news/allston_brighton/2012/09/mbta_to_hold_meeting_on_20m_pr.html |title=MBTA to hold meeting on $20m project to rebuild Boston College Station |newspaper=Boston Globe |date=September 28, 2012 |author=Rocheleau, Matt}}</ref><ref>{{cite web |archive-url=https://web.archive.org/web/20100102134313/http://mbta.com/uploadedfiles/Riding_the_T/Accessible_Services/Accessible_Services_List/Accessibility%20Calendar.pdf |archive-date=2 January 2010 |url=https://www.mbta.com/uploadedfiles/Riding_the_T/Accessible_Services/Accessible_Services_List/Accessibility%20Calendar.pdf |title=Access in Motion: 2009 Calendar |year=2009 |publisher=Massachusetts Bay Transportation Authority}}</ref> A reconstruction of {{bts|Brookline Hills}} (replacing lifts) was completed in 2022.<ref>{{cite web |url=https://www.mbta.com/projects/brookline-hills-station-accessibility-improvements |title=Brookline Hills Station Accessibility Improvements |date=January 10, 2022 |publisher=Massachusetts Bay Transportation Authority}}</ref>  Construction of two accessible stations ({{bts|Babcock Street}} and {{bts|Amory Street}}) on the B branch to replace four non-accessible stations took place in 2021.<ref>{{cite press release |url=https://www.mbta.com/projects/green-line-b-branch-station-consolidation/update/new-babcock-street-and-amory-street |title=New Babcock Street and Amory Street Stations Open November 15 |date=November 12, 2021 |publisher=Massachusetts Bay Transportation Authority}}</ref> Temporary work to make {{bts|Newton Highlands}} accessible was done in 2019, followed by the four remaining D branch stations in 2024; larger reconstructions of the five stations are planned for later in the 2020s.<ref name=SWADec2024 /> Several other surface accessibility projects are planned:
*The nine remaining non-accessible B branch stations are to be reconstructed in 2025–2027. Consolidations will reduce the nine stops to six.<ref name=SWADec2024 />
*The nine remaining non-accessible C branch stations are to be reconstructed in 2025–2026. Consolidations will reduce the nine stops to seven.<ref name=SWADec2024 />
*The four remaining non-accessible E branch stations are to be reconstructed in 2027–2029. Consolidations will reduce the four stops to two.<ref name=SWADec2024 />
{{clear left}}
===Core Capacity Program===
In the late 2010s, the MBTA began planning a capital project to meet future capacity needs that year on the Green Line. A study completed in 2018 settled on the size for Type 10 vehicles and evaluated infrastructure needed to support the new vehicles. In 2022, the MBTA entered the project development phase for the [[Federal Transit Administration]] Capital Investment Grants Program, which provides funding for "core capacity" projects on crowded sections of existing transit systems. {{As of|April 2025}}, the MBTA intends to enter the engineering phase by mid-2025, with the full funding grant agreement expected in late 2028 and construction lasting through the mid-2030s. In April 2025, the MBTA Board approved plans for the $3.8 billion Core Capacity Program, of which half ($1.9 billion) would be federally funded. It includes:<ref>{{cite web |url=https://cdn.mbta.com/sites/default/files/2025-04/2-GLT-CoreCapacityBoardBriefing-April2025.pdf |title=Green Line Transformation (GLT) Core Capacity Program: Overview and status of the Core Capacity Program |date=April 24, 2025 |publisher=Massachusetts Bay Transportation Authority}}</ref>
*Signal upgrades, new crossovers, and other work in the Central Subway
*Systemwide overhead catenary relocation
*Traction power improvements on the D Branch
*Modifications to the Riverside, Reservoir, Lake Street, and Inner Belt yards
*Accessibility and infrastructure work on the B and E branches
*58 additional Type 10 vehicles
*A test track between Chestnut Hill and Newton Centre for Type 10 vehicles
*Upgrades to a Type 10 simulator for operators

==Station listing==
This listing includes only the Green Line section between {{bts|Lechmere}} and {{bts|Kenmore}}, which are served by multiple branches. For stops served by only one branch, see {{section link|Green Line B branch#Station listing}}, {{section link|Green Line C branch#Station listing}}, {{section link|Green Line D branch#Station listing}}, and {{section link|Green Line E branch#Station listing}}. All stations in the central subway have [[paid area|prepaid fare areas]] ([[fare control]]).

{| class="wikitable"
|-
!Location
!Station
!Branches
!Opened
!Notes and connections
|-
|[[East Cambridge, Massachusetts|East Cambridge]]
|{{Access icon}} {{bts|Lechmere}}
|rowspan=4|D, E
|March 21, 2022
|The [[Lechmere Viaduct]] opened on June 1, 1912, with a direct connection to surface lines until July 9, 1922. The surface station was open from July 10, 1922, to May 23, 2020. <br />{{ric|MBTA|Bus|name=y}}: {{MBTA bus links|Lechmere}}<br />{{bus icon}} {{MBTA other buses|Lechmere}}
|-
|[[West End, Boston|West End]]
|{{access icon}} {{bts|Science Park}}
|August 20, 1955
|
|-
|rowspan=2|[[North End, Boston|North End]]
|{{Access icon}} {{bts|North Station|Green}}
|June 28, 2004
|Original surface station was open from September 3, 1898, to March 27, 1997. Elevated station was open from June 1, 1912, to June 24, 2004.<br />{{ric|MBTA|Subway|name=y}}: {{ric|MBTA|Orange|name=y}}<br />{{ric|MBTA|Commuter Rail|name=y}}: [[Fitchburg Line|Fitchburg]], [[Lowell Line|Lowell]], [[Haverhill Line|Haverhill]], [[Newburyport/Rockport Line|Newburyport/Rockport]]<br />{{ric|MBTA|Bus|name=y}}: {{MBTA bus links|North Station}}<br />{{ric|Amtrak|name=y}}: {{lnl|Amtrak|Downeaster}}<br />{{bus icon}} {{MBTA other buses|North Station}}
|-
|{{Access icon}} {{bts|Haymarket}}
|rowspan=2|September 3, 1898
|{{ric|MBTA|Subway|name=y}}: {{ric|MBTA|Orange|name=y}}<br />{{ric|MBTA|Bus|name=y}}: {{MBTA bus links|Haymarket}}
|-
|rowspan=3|[[Downtown Boston]]
|{{Access icon}} {{bts|Government Center}}
|rowspan=5|B, C, D, E
|{{ric|MBTA|Subway|name=y}}: {{ric|MBTA|Blue|name=y}}<br />{{ric|MBTA|Bus|name=y}}: {{MBTA bus links|Government Center}}
|-
|{{Access icon}} {{bts|Park Street}}
|rowspan=2|September 1, 1897
|{{ric|MBTA|Subway|name=y}}: {{ric|MBTA|Red|name=y}}, {{ric|MBTA|Silver|name=y}} ({{MBTABus|SL5}})<br />{{ric|MBTA|Bus|name=y}}: {{MBTA bus links|Park Street}}<br />At {{bts|Downtown Crossing}}: {{ric|MBTA|Subway}} {{ric|MBTA|Orange|name=y}}; {{ric|MBTA|Bus}} {{MBTA bus links|Downtown Crossing}}
|-
|{{bts|Boylston}}
|{{ric|MBTA|Subway|name=y}}: {{ric|MBTA|Silver|name=y}} ({{MBTABus|SL5}})<br />{{ric|MBTA|Bus|name=y}}: {{MBTA bus links|Boylston}}
|-
|rowspan=3|[[Back Bay, Boston|Back Bay]]
|{{Access icon}} {{bts|Arlington}}
|November 13, 1921
|{{ric|MBTA|Bus|name=y}}: {{MBTA bus links|Arlington}}
|-
|{{Access icon}} {{bts|Copley}}
|rowspan=2|October 3, 1914
|{{ric|MBTA|Bus|name=y}}: {{MBTA bus links|Copley Square}}
|-
|{{bts|Hynes Convention Center}}
|rowspan=2|B, C, D
|{{ric|MBTA|Bus|name=y}}: {{MBTA bus links|Hynes Convention Center}}
|-
|[[Fenway–Kenmore]]
|{{Access icon}} {{bts|Kenmore}}
|October 23, 1932
|{{ric|MBTA|Bus|name=y}}: {{MBTA bus links|Kenmore}}<br />At {{bts|Lansdowne}}: {{ric|MBTA|Framingham/Worcester|name=y}}
|}

==Incidents and collisions==
[[File:2008 Green Line wreck.png|thumb|left|Type 7 LRV car wrecked in the May 2008 crash]]
On May 28, 2008, [[2008 Massachusetts train collision|two D branch trains collided]] in [[Newton, Massachusetts|Newton]]. The operator of one of the trains was killed and numerous riders were taken to area hospitals with injuries of varying degrees of seriousness. While it was originally thought that cell phone use was responsible for the crash, the cause was officially determined to be an episode of [[micro-sleep]] caused by the driver's [[sleep apnea]].<ref>{{cite report |url=https://www.ntsb.gov/investigations/AccidentReports/Reports/RAR0902.pdf |title=Collision Between Two Massachusetts Bay Transportation Authority Green Line Trains, Newton, Massachusetts, May 28, 2008 (NTSB/RAR-09-02) |date=July 14, 2009 |publisher=National Transportation Safety Board |archive-url=https://web.archive.org/web/20111016122407/http://www.ntsb.gov/doclib/reports/2009/RAR0902.pdf |archive-date=October 16, 2011 |url-status=dead}}</ref>

On May 8, 2009, two trolleys rear-end collided underground between Park Street and [[Government Center (MBTA station)|Government Center]] when the driver of one of the trolleys, 24-year-old Aiden Quinn, was [[Texting while driving|text messaging his girlfriend while driving]].<ref>[http://www.thebostonchannel.com/news/19411812/detail.html "Trolley Driver Was Texting Girlfriend At Time Of Crash: 46 Injured In Green Line Crash"] {{webarchive|url=https://web.archive.org/web/20120222052240/http://www.thebostonchannel.com/news/19411812/detail.html |date=February 22, 2012 }}, WCVB, Boston, May 8, 2009.</ref> Quinn had run through a red light before the crash, which injured 46 people. MBTA officials estimated that the cost of the crash was $9.6&nbsp;million.<ref>[https://abcnews.go.com/US/story?id=7561561&page=1 Texting Trolley Driver Is Transgendered Male], ABC News, May 11, 2009</ref> A strict ban on cell phone usage by MBTA operators was later enacted.<ref>[http://www.thebostonchannel.com/news/19417457/detail.html "Trolley Crash Inspires Tougher Cell Phone Policy: NTSB Still Investigating Crash"] {{webarchive|url=https://web.archive.org/web/20120222052251/http://www.thebostonchannel.com/news/19417457/detail.html |date=February 22, 2012 }}, WCVB, May 9, 2009</ref>

On October 8, 2012, two E branch trolleys collided in the 700 block of [[Huntington Avenue]] near [[Brigham Circle]] when one derailed into the other, injuring three people including a train operator.<ref>{{Cite web |date=October 8, 2012 |title=MBTA: Human error caused Green Line collision, derailment |url=https://www.wcvb.com/article/mbta-blames-human-error-for-green-line-trolley-derailment-along-huntington-ave/8174408 |access-date=September 17, 2024 |website=WCVB}}</ref>  The next month on November 29, two trolleys collided at low speed at [[Boylston (MBTA station)|Boylston]], injuring several dozen passengers.<ref>{{cite news |url=http://www.boston.com/metrodesk/2012/11/29/trolley-accident-reported-boylston-mbta-station/AFHlk9odLmBbDl87XLRqIO/story.html |title=35 taken to hospital after two trolleys collide at Boylston MBTA station |newspaper=Boston Globe |date=November 29, 2012 |access-date=November 29, 2012 |author=Moskowitz, Erik|display-authors=etal}}</ref>

On March 10, 2014, a D branch trolley with passengers aboard derailed in the tunnel just west of Kenmore Station, near the [[flat junction]] between the "D" and "C" branches. A second train had to brake suddenly to avoid hitting the derailed train.<ref name=Tempera>{{cite news|last=Tempera|first=Jacqueline; Martine Powers|title=Seven injured as MBTA Green Line train derails near Kenmore Station|url=http://www.boston.com/news/local/massachusetts/2014/03/10/mbta-green-line-train-derails-injuries-reported/mebqIRRfKbyQDazLTPMpBK/story.html|access-date=March 11, 2014|newspaper=Boston.com|date=March 10, 2014}}</ref> Ten people were treated for moderate injuries.<ref>{{cite web|url=http://bostonherald.com/news_opinion/local_coverage/herald_bulldog/2014/03/green_line_train_derails_10_reported_injuries|title=Green Line train derails; 'it was intense'|work=Boston Herald|date=March 10, 2014|access-date=March 10, 2014|archive-date=March 11, 2014|archive-url=https://archive.today/20140311020513/http://bostonherald.com/news_opinion/local_coverage/herald_bulldog/2014/03/green_line_train_derails_10_reported_injuries|url-status=dead}}</ref>

In October 2016, ''[[The Boston Globe]]'' reported that the Green Line had the highest number of derailments and collisions on light rail lines in the United States in 2015. The number of incidents had been increasing for several years due to deferred maintenance on tracks and wheels, which resulted in more low-speed derailments of Type 8 cars.<ref>{{cite news |last=Dungca |first=Nicole |url=https://www.bostonglobe.com/metro/2016/10/12/green-line-suffered-little-noticed-string-derailments-over-past-two-years/xZhLbzp01WLdBs9hhO9NNN/story.html |title=The Green Line had the most derailments in the nation last year |newspaper=[[The Boston Globe]] |date=October 13, 2016 |access-date=October 13, 2016}}</ref>

On July 30, 2021, two B branch trains collided at {{bts|Babcock Street}}, causing 25 injuries.<ref>{{cite news |url=https://www.bostonglobe.com/2021/07/31/metro/green-line-service-restored-following-friday-night-crash/ |title=NTSB investigating Green Line crash that left 25 injured; MBTA operator placed on leave |newspaper=Boston Globe |date=July 31, 2021 |first=Laura |last=Crimaldi}}</ref>

On October 1, 2024, a train derailed near [[Lechmere station|Lechmere]], injuring seven people and disrupting service on the [[Green Line Extension]].<ref>{{Cite web |last=Becker |first=Kaitlin McKinley |date=2024-10-01 |title=Green Line train derails near Cambridge MBTA station; 7 people injured |url=https://www.nbcboston.com/news/local/green-line-train-derails-near-cambridge-mbta-station-injuries-reported/3506328/ |access-date=2024-10-02 |website=NBC Boston}}</ref><ref>{{Cite web |date=2024-10-02 |title=Shuttle Buses Continue to Replace Green Line Service between North Station and Union Square and Medford/Tufts |url=https://www.mbta.com/news/2024-10-02/shuttle-buses-continue-replace-green-line-service-between-north-station-and-union |access-date=2024-10-02 |website=www.mbta.com}}</ref> Regular service resumed on October 3. The [[National Transportation Safety Board]], [[Federal Transit Administration]], and Massachusetts Department of Public Utilities are investigating the derailment.<ref>{{Cite web |date=2024-10-03 |title=Green Line Service Has Resumed between North Station and Union Square and Medford/Tufts |url=https://www.mbta.com/news/2024-10-03/green-line-service-has-resumed-between-north-station-and-union-square-and |access-date=2024-10-03 |website=www.mbta.com}}</ref> A preliminary NTSB report noted the train was going 36&nbsp;mph in a 10&nbsp;mph zone and passed through a double red signal that required a stop. The train passed through a switch that was still moving into position, causing part of the first truck of the lead car to go straight and the rest of the train into the diverging track and causing the derailment.<ref>{{Cite web |url=https://www.ntsb.gov/investigations/Pages/RRD24FR017.aspx|title=Massachusetts Bay Transit Authority Derailment|access-date=2024-10-17|website=National Transportation Safety Board}}</ref>

On February 9, 2025, a E branch train crashed into an out of service train at [[East Somerville station|East Somerville]], injuring five people.<ref>{{Cite web |last=Glaun |first=Dan |date=2025-02-09 |title=Five taken to hospital after Somerville Green Line collision |url=https://www.bostonglobe.com/2025/02/09/metro/five-hospitalized-in-somerville-green-line-collision/ |access-date=2025-02-09 |website=The Boston Globe |language=en-US}}</ref>

In 2009, the [[National Transportation Safety Board]] recommended that the Green Line be outfitted with [[positive train control]] to prevent collisions as part of its various crash investigations. The MBTA decided in 2012 not to implement PTC, estimating the cost at $645 million to $721 million. In 2015, as crashes continued to happen, the NTSB complained the agency was moving too slowly identifying a feasible alternative. In 2019, the MBTA awarded a contract to implement a similar safety system by 2024, at a cost of $170 million. A train would automatically brake if a driver violated a traffic signal, or if cameras or radar detected an obstacle.<ref>{{cite news |newspaper=[[The Boston Globe]] |url=https://www.bostonglobe.com/2021/08/15/metro/ts-green-line-another-serious-crash-questions-about-lack-safety-technology/ |title=On the T's Green Line, another serious crash and questions about the lack of safety technology |author1=Laura Crimaldi |author2=Elizabeth Koh Globe |date=August 15, 2021}}</ref> That contract was cancelled in June 2024.<ref name="GLTPS scrapped" /> A new contract was awarded in February 2025 for [[#Positive train control|a new system]] that would provide warnings to operators by the end of 2025, and enforce violations with automatically braking by mid-2028.<ref name="boardmeeting20250225" />

==References==
{{reflist}}

==External links==
{{commons category}}
{{Attached KML}}
*[https://www.mbta.com/schedules/Green MBTA – Green Line]

{{MBTA}}
{{MBTA light rail vehicles}}
{{USLightRail}}
{{North American legacy streetcar systems}}

[[Category:Green Line (MBTA)| ]]
[[Category:Standard-gauge railways in the United States]]
[[Category:Railway lines opened in 1897]]
[[Category:1897 establishments in Massachusetts]]
[[Category:600 V DC railway electrification]]