MBTA Subway Lines: Red, Orange, Blue, Green, Silver

Boston runs the oldest subway in the country, and it shows in the best and worst ways. The lines are colour-coded, which is genuinely helpful, and then several of them split into branches, which is where visitors come unstuck.

The lines

Red Line runs from the northwest, through Cambridge past Harvard and MIT, under the river into Downtown, and then splits in Dorchester into two southern branches. Boarding a southbound Red Line train without checking which branch it takes is the classic first-week mistake. The Red Line also carries the heaviest concentration of universities of any line in the system, which shapes its ridership and its rhythm across the academic year.

Orange Line runs north to south through the middle of the city, from Malden down through Downtown and out to Forest Hills in Jamaica Plain. It serves several of the densest and most rapidly changing neighbourhoods in the city.

Blue Line runs from Downtown northeast under the harbour toward Revere, and it serves Logan Airport, with a shuttle bus connection from the Airport station to the terminals. It is the shortest of the heavy rail lines and the only one that goes under the harbour rather than the river.

Green Line is the oldest part and the most complicated: light rail, partly underground downtown and partly on the surface, splitting into branches lettered B, C, D and E running to different western and northern destinations. The tunnel section beneath downtown dates to the 1890s and is the oldest subway tunnel in North America. The Green Line Extension opened its Medford branch in December 2022, which is why the E branch now runs to Medford/Tufts and the D branch to Union Square in Somerville.

Silver Line is bus rapid transit rather than rail, though it appears on the rapid transit map, which causes reasonable confusion. Some Silver Line routes serve the Seaport and run to Logan Airport directly.

The branch problem

The Green Line and the Red Line both split. This is the single most important operational fact for anyone new to the system.

On the Green Line, a train's letter tells you which branch it serves. The lettered branches diverge west of the downtown tunnel, so a train that is correct for the first several stops becomes wrong at the junction. Boarding the wrong letter means an unplanned tour of a neighbourhood you did not intend to visit.

On the Red Line, southbound trains serve one of two branches, and the signage on the train tells you which. Northbound this does not matter; southbound it entirely does.

The rule for both: read the destination on the front of the train, not just the colour on the map. This one habit prevents more wasted time than anything else you can learn about the system.

Getting to Logan

Two reasonable options, and which is better depends entirely on where you start.

The Blue Line to Airport station, then the shuttle bus to the terminals. Best from the north side of downtown and anywhere along the Blue Line.

The Silver Line from South Station, which serves the airport directly without a separate shuttle. Best if you are coming from South Station, the Seaport, or arriving by commuter rail or intercity train.

There is also a water shuttle across the harbour, which is the most pleasant option in decent weather and the one almost nobody thinks of.

Frequency, reliability and works

This is an old system carrying a modern load, and the MBTA has been running an extended programme of track and signal work to address years of deferred maintenance. Speed restrictions imposed for safety reasons were a defining feature of recent years, and the sustained effort to remove them is the main story of the system's recent operations.

The practical consequence for a rider is that planned diversions are frequent. Segments close at weekends, shuttle buses replace trains, and a line that is on the map is not necessarily running trains on the day you want it.

Check for planned works before you travel, particularly at weekends and particularly if you are going to the airport or to something time-sensitive.

Accessibility

Station accessibility varies considerably, which is what happens when a network is assembled over more than a century. Many stations are fully accessible; some older ones are not, and some are accessible in one direction only.

If step-free access matters, check the specific stations on your route rather than assuming, and note that a lift out of service can make an otherwise accessible station unusable. The MBTA publishes lift status, and checking it before setting out is worth the thirty seconds.

What the system does well

For all the complaints, and Bostonians complain about the T with real enthusiasm, the network reaches into dense neighbourhoods that a system built later around highways would have skipped entirely.

Boston is genuinely usable without a car in a way most American cities are not, and that is a direct consequence of the subway being built early, when the city was already dense and the streets already existed. The age that causes the maintenance backlog is the same age that produced the coverage.

The short version

Read the front of the train. Check for weekend works. Use the Blue Line to Logan from the north and the Silver Line from South Station. And do not assume a walk is longer than a ride: downtown Boston is small, the stations are close together, and walking one stop is frequently faster than waiting for a train.

Commuter rail, briefly

Beyond the coloured lines sits an extensive commuter rail network radiating from two downtown terminals, North Station and South Station, out across eastern Massachusetts and into Rhode Island.

The two-terminal arrangement is a long-standing quirk: the network is split in half, and there is no through-running between north-side and south-side lines. Connecting between them means crossing downtown by subway or on foot. Proposals to link them have been discussed for decades.

For visitors, the useful point is that commuter rail reaches places the subway does not, including Salem, Concord, Providence and the South Shore, and that some in-city stops are faster by commuter rail than by subway.

Buses and the Silver Line

The bus network carries an enormous share of total ridership and reaches most of what rail does not. Several routes are designated key routes with higher frequency.

The Silver Line's airport branches are effectively free inbound from the airport, which is a detail worth knowing and which surprises arriving visitors who expect to pay.

Ferries

The MBTA runs harbour ferry service, which is a genuine commuting option for parts of the South Shore and East Boston and an extremely pleasant way to move around the harbour in decent weather. It is priced separately from the subway.

Practical habits for the T

Stand right, walk left on escalators, which is enforced socially rather than by signage.

Let people off first. Boston platforms are narrow and this matters more here than in systems with wider platforms.

Check whether your station has separate entrances by direction. Several older stations do, and entering the wrong one means paying again or a long walk to cross over.

Download a live tracking app. Real-time arrival information is available and is considerably more reliable than the printed schedule, particularly on the Green Line surface branches.