The Massachusetts Bay Transportation Authority (MBTA) maintains a large public transit system in the Boston, Massachusetts area, and uses various methods to name and number their services for the convenience of users.
The subway system consists of four trunk lines, all of which meet downtown. Each is assigned a color, as follows:
The Red Line has two branches, in the south, called by their terminals – Ashmont and Braintree. Additionally, the Ashmont–Mattapan High Speed Line, a streetcar line to Mattapan, is also colored red. Some trains use the letters A, B, and C for Ashmont, Braintree and Alewife (the north terminal) respectively.
The Green Line is a streetcar/light rail system with four branches to the west, labeled "B" to "E" from north to south. The trains operate underground in the downtown area; outside of downtown, all but the "D" branch run along city streets, with frequent grade crossings at intersections. Rollsigns and newer electronic signs use the following labels:
Until 1965, the lines were called by their names:
They were also known by various numbers, used only on maps (see below for more details), as part of an integrated system of rapid transit, streetcars and buses:
After taking over operations in August 1964, the MBTA began rebranding many elements of Boston's public transportation network. On August 26, 1965, the four rapid transit lines were assigned colored names related to their history and geography. The Red Line was named for Harvard University's crimson branding, the Blue Line for passing under Boston Harbor and along Revere Beach, the Green Line for running along the Emerald Necklace, and the Orange Line for running under a section of Washington Street originally known as Orange Street.[1] [2] When designing the rebranding, Cambridge Seven Associates originally planned for yellow instead of orange, but yellow was rejected after testing.[3]
On August 26, 1965, the current colors were assigned. The Green Line branches were lettered A to E in 1967, ending the use of map numbers for the remaining rail routes. The A branch was discontinued in 1969, before lettered rollsigns were ever used on the line.[4] As cars were interchangeable between the Green Line and Ashmont–Mattapan Line, rollsigns also included the letter F for Mattapan service, but this was later changed to M. http://world.nycsubway.org/perl/show?35539
On some later rollsigns, short-turn trips were displayed with a slash through the letter. This use included:
Many rollsigns only use the letters for outbound trips, with no letters next to downtown destinations. When the letters were first applied, the inbound destinations all used letters.http://groups-beta.google.com/group/misc.transport.urban-transit/messages/0d2cdf18207974f5,900589f582f46d05,1374c25c232cceb5,d85cdcf8689369d2,51ec5512f2f5ddfe,b0e411bbf4100e9a,3dd0d276d23e57db,8544edf31aae63df,0f7d89eb1223fd41,1a0fc52080217d24?hl=en&thread_id=a39e96e4ecc836ca&mode=thread&noheader=1&_done=%2Fgroup%2Fmisc.transport.urban-transit%2Fbrowse_frm%2Fthread%2Fa39e96e4ecc836ca%2Fa9a23545f09a35c6%3F#doc_d85cdcf8689369d2
The Red Line branches were initially assigned letters in 1968 – A for Quincy/South Braintree and C for Ashmont. At the time, a branch to Brockton was being planned, which might have gotten the letter B. These letters were never used much, and never appeared on maps, and newer rollsigns omitted them. In 1994 the current letter coding was assigned with new cars.
Bus routes are assigned numbers, which are displayed on maps and buses. Generally, the numbers increase from South Boston clockwise to East Boston. Numbers above 202 are used by outlying routes, assigned by region as follows:
The Silver Line Phase I (Washington Street) service have SL4 & SL5. SL5 to Downtown Crossing is internally the 749, as it replaced the 49. The SL4 to South Station is internally 751. The branches of Phase II (South Boston Waterfront) are assigned labels SL1, SL2, and SL3. Shuttles running only to Silver Line Way are not labeled. Internally, the shuttle is 746, and the branches are SL1 as 746.1 or 741 to Logan Airport in East Boston, SL2 as 746.2, or 742 to Design Center in South Boston, and SL3 as 743 to Chelsea.
The two (formerly three) crosstown routes are publicly assigned CT1 to CT3. Internally, they too are given 700-series numbers, based on a parallel route. The former CT1 mostly ran the same route as the 1, so it was the 701. Part of the CT2 parallels the 47, so that part is the 747, and a more recent extension is the 748 (always through-routed). The CT3, paralleling the 8, is the 708, and the former extension was the 709.
Night Owl buses were assigned in the 700 series as well (with a suffix of N). Night Owl buses that replaced other buses were given the normal bus number with N.
Additionally, several private bus companies are subsidized by the MBTA. Some of those are assigned numbers from 710 to 716.
The first numbers used were implemented with Hunter sign boxes, approximately from 1910 to 1917. Numbers were three digits, with the first referring to the division.[5] In 1918, the network was substantially reorganized, and numbers were no longer used. However, from then until 1967, a similar four-digit system was used internally.
Numbers resembling the current system were first assigned on the 1936 map. However, until the 1942 edition, the numbers changed with each new printing as routes were added and removed. In addition, these routes were only used on the map, not even on schedules. From 1942 on, the numbers generally remained the same, with a minor renumbering in 1967 prior to implementing the numbers on rollsigns and schedules.
As the MBTA began to take over suburban bus systems, it assigned them numbers in higher ranges.
The Eastern Massachusetts Street Railway's buses were taken over on March 30, 1968, and numbers were assigned as follows:
The Middlesex and Boston Street Railway buses were subsidized by the MBTA in September 1964, and they were assigned numbers from 20 to 36 (extended to 39 in November 1967, on the takeover of routes from Transit Bus Lines), duplicating existing MBTA numbers. The MBTA took over the M&B on June 30, 1972, and added a 5 in front. The routes were given unused numbers from 52 to 76 in September 1982, and in 1996 the ones operating express to downtown Boston via the Mass Pike were again assigned a 5 in front.