Subway
The Massachusetts Bay Transportation Authority (MBTA)—known as "the T"—operates subways, buses, and trolleys along five connecting lines, as well as many bus and several rail commuter lines that reach nearby suburbs and cities. Subways and buses operate from about 5:30 am to about 1 am, with limited late-night service. A 24-hour hotline and the MBTA website have specific information on routes, schedules, fares, wheelchair access, and other matters. Free maps are available at the MBTA's Park Street Station information stand, open daily from 7 am to 10 pm. The MBTA website has a useful trip planner tool.
Getting Around on the Subway
"Inbound" trains head into the city center (Park Street Station) and "outbound" trains head away from it. If you get on the Red Line at South Station, the train heading toward Alewife (Cambridge) is inbound. But once you reach Park Street, the train becomes outbound. Similarly, the Green Line to Fenway Park would be the Boston College or Cleveland Circle train. Large maps prominently posted at each station show the line(s) that serve it, with each stop marked; small maps are overhead in each car. Free 24-hour shuttle buses connect Airport Blue Line Station with all airline terminals. Shuttle Bus 22 runs between the subway and Terminals A and B, and Shuttle Bus 33 runs between the subway and Terminals C and E.
The Red Line originates at Braintree and Quincy Center to the south; the routes join near South Boston at the JFK/UMass stop and continue to Alewife, the northwest corner of Cambridge by suburban Arlington. (The Mattapan high-speed line, or M-line, is considered part of the overall Red Line. Originating in Ashmont Station, it transports passengers via vintage yellow trolleys to Mattapan Square.)
The Green Line operates elevated trolleys that dip underground in the city center. The line originates at Cambridge's Lechmere, heads south, and divides into four westward routes: B ends at Boston College (Commonwealth Avenue); C ends at Cleveland Circle (Beacon Street, in Brighton); D ends at Riverside (Newton at Route 128); and E ends at Heath Street (Huntington Avenue in Jamaica Plain).
The Blue Line runs weekdays from Bowdoin Square (and weeknights and weekends from Government Center) to the Wonderland Racetrack in Revere, north of Boston. The Blue Line is best if you're heading to North Station, Faneuil Hall, North End/Waterfront, or Back Bay (the Hynes Convention Center, Prudential Center area). The Orange Line runs from Oak Grove in north suburban Malden southwesterly to Forest Hills near the Arnold Arboretum in Jamaica Plain.
The Silver Line (a bus line with its own dedicated lanes) has four routes. SL1 connects South Station to Logan Airport; SL2 runs between South Station and the Design Center; SL4 connects Dudley Square and South Station; and SL5 runs between Downtown Crossing and Dudley Square, also stopping in Boylston.
Fares and Passes
T fares are $2.75 for adults paying in cash or $2.25 with a reloadable CharlieCard. Bus fares are $2 ($1.70 with a CharlieCard). The SL1 and SL2 bus lines are priced as if they were part of the subway. Children ages 11 and under ride free. Senior citizens and students with proper ID pay $1.10. Fares on the commuter rail—the Purple Line—vary from $2.25 to $12.50, depending on distance, but are much more expensive if you pay cash on-board.
Getting a CharlieCard makes it easier to transfer between the subway and the bus, because such transfers are free and you don't need to keep track of individual tickets. Get your CharlieCard from a ticket agent at subway terminals during business hours (7 am to 7 pm); from a machine at the T stations at North Station, South Station, or Back Bay; the CharlieCard office at Downtown Crossing; or online or from some retailers. Check the T's website for detailed information.
One-day ($12) and seven-day ($21.25) passes are available for unlimited travel on subways, city buses, and inner-harbor ferries. Buy passes at any full-service MBTA stations. Passes are also sold at the Boston Common Visitor Information Center and at some hotels.