Subway vs. bus — what's different
The MBTA runs buses, subway lines, and the Green Line (which acts like a streetcar in some places and a subway in others). They're all part of the same system, but the experience is different enough that it helps to know what you're walking into.
Buses
Stop every few blocks; you board at the front. Tap your Charlie Card or phone on the reader by the driver. You can exit from any door — just push the yellow strip or pull cord to request your stop. Buses run on the street, so timing can vary with traffic. The posted schedule is a suggestion, not a promise — check real-time arrivals in the app.
Subway (Red, Orange, Blue lines)
Runs underground on its own tracks, so it's generally faster and more predictable than buses. You tap in at the fare gate, wait on the platform, and board any car. Trains don't have stop-request buttons — they stop at every station. Signs on the platform and announcements will tell you which direction you're headed (e.g. "Alewife" vs. "Ashmont/Braintree" on the Red Line).
The Green Line
The weird one. Parts run underground like a subway (downtown). Other parts run above ground at street level like a trolley (the B, C, and E branches). When it's above ground, you board at small platform stops on the street — look for the green signs. It can feel unfamiliar, but it works the same way: tap on, ride, get off at your stop.
Free transfers
If you pay with a Charlie Card or phone, a single bus-to-subway transfer is free within two hours. So a trip that mixes buses and trains often costs just a single fare.