What is the easiest and fastest way to get from the Back Bay train station, in Boston, to the North station?

You get off your train at Back Bay, go up the escalater, walk over to the Orange Line entrance, go down the stairs, wait on the Inbound (Oak Grove) side of the platform, take the train to North Station. Follow the signs to the Commuter Rail platforms (Amtrak comes in there.)

Ignore advice to get on the Green Line. Don't bother with a cab. Both are much slower than simply taking the Orange Line.

Have a great trip on the Downeaster. It's one of Amtrak's best routes.

Back Bay has an Orange line stop. So does North Station. Get off of your Amtrak or commuter rail train, and get on an Orange line train inbound. Stay on it until you get to North Station. Then go inside the TD BankNorth Garden to get the train to Portland.

You have to walk down the street to the Copley T station, take the green line inbound to North Station.

Best and easiest is a cab ($10 or so).

Second best option is the the Orange Line.

Go to coply station, Green Line on the Subway (T)

Or you can go to Oak Grove like the MBTA website (www.mbta.com) says

http://mbta.com/rider_tools/trip_planner/default.a...

and here is a better map

http://maps.google.com/maps?f=q&source=s_q&hl=en&g...