Metropolitan Transit Authority (Boston)

Massachusetts Bay Transportation Authority

The MBTA provides services in five different modes (boat not pictured) around Greater Boston.
Overview
Locale	Greater Boston
Transit type	Bus bus rapid transit ferryboat light rail heavy rail regional rail trolleybus
Number of lines	179 (bus) 4 (BRT) 4 (ferryboat) 5 (light rail) 4 (heavy rail) 13 (commuter rail) 4 (trolleybus)
Number of stations	22 (BRT) 74 (light rail) 51 (heavy rail) 123 (regional rail)
Daily ridership	1,277,200 (weekday, Q4 2015)
Chief executive	Luis Ramirez
Headquarters	Massachusetts State Transportation Building 10 Park Plaza, Boston, MA 02116
Website	mbta.com
Operation
Began operation	1897 (light rail) 1901 (heavy rail) 1964 (MBTA)
Operator(s)	MBTA (most bus, BRT, heavy rail, trolleybus, light rail) Harbor Express/Boston Harbor Cruises (ferryboat) Keolis Commuter Services (regional rail) Various contractors (700-series bus routes)
Technical
System length	1,193 miles (1,920 km) (total) 8 miles (13 km) (BRT) 751 miles (1,209 km) (bus and trackless trolley) 26 miles (42 km) (light rail) 38 miles (61 km) (heavy rail) 368 miles (592 km) (regional rail)
Track gauge	4 ft 8 1⁄2 in (1,435 mm)

The Massachusetts Bay Transportation Authority (abbreviated MBTA and known colloquially as The T) is the public agency responsible for operating most public transportation services in Greater Boston, Massachusetts. Earlier modes of public transportation in Boston were independently owned and operated; many were first folded into a single agency with the formation of the Metropolitan Transit Authority (MTA) in 1947. The MTA was replaced in 1964 with the present-day MBTA, which was established as an individual department within the Commonwealth of Massachusetts before becoming a division of the Massachusetts Department of Transportation (MassDOT) in 2009.

The MBTA and Philadelphia's Southeastern Pennsylvania Transportation Authority (SEPTA) are the only U.S. transit agencies that operate all five major types of terrestrial mass transit vehicles: light rail vehicles (the Ashmont–Mattapan High Speed and Green Lines); heavy rail trains (the Blue, Orange, and Red Lines); regional rail trains (the Commuter Rail); electric trolleybuses (the Silver Line); and motor buses (MBTA Bus). In 2016, the system averaged 1,277,200 passengers per weekday, of which the subway averaged 552,500 and the light-rail lines 226,500, making it the fourth-busiest subway system and the busiest light rail system in the United States.