

See also: Massachusetts Bay Transportation Authority § History This also marked the beginning of subway traffic in the United States. History Streetcar number 1752, driven by the veteran motorman Jimmy Reed, is shown here after it became the first revenue car in the Boston subway system on September 1, 1897. (Only the short-lived Beach Pneumatic Transit demonstration line in New York City was built before.) The section of the Tremont Street subway between Park Street and Boylston Street stations, now on the Green Line, opened in 1897, making it the oldest transit subway in the United States still in use. In the same period, the light rail lines had 30,705,000 rides, or about 100,000 per weekday, and comprised the third-busiest light rail system in the United States.

In 2022, the heavy rail lines had 80,969,900 rides, or about 274,700 per weekday in the second quarter of 2023, and comprised the fourth-busiest heavy rail system in the United States. Three branches operate underground and charge rapid transit fares two branches operate entirely on the surface and charge lower bus fares. The five branches of the Silver Line bus rapid transit network are also shown as part of the rapid transit system. All except the Ashmont–Mattapan line operate in tunnels in the downtown area, but no route operates entirely underground, and only 31 out of the system's 147 stations are located underground. The color-branded lines consist of three heavy rail lines ( Red, Orange, and Blue), one branched light rail system ( Green), and a short light rail line (the Ashmont–Mattapan High-Speed Line, colored as part of the Red Line). The Massachusetts Bay Transportation Authority (MBTA) operates rapid transit (heavy rail), light rail, and bus rapid transit services in the Boston metropolitan area, collectively referred to as the rapid transit, subway, or the T system. Massachusetts Bay Transportation Authority (MBTA) Red Line train entering Alewife station in November 2019
