Originally Posted by ordogg
I'm heading to BWI for a conference in the Marriott by the harbor in 2 weeks, and would like to public transportation (because I have time and always enjoyed trains & planes) - is it better to take the light rail or the amtrak/MARC service?
Definitely take the light rail. The station is directly connected to the E Pier (International terminal) and you won't need to transfer. The light rail follows Howard Street downtown; get off at the Convention Center and walk one block west to Eutaw Street, which runs parallel to Howard. The Marriott Inner Harbor is on Eutaw between Pratt (south side) and Lombard (north).
The heavy rail that serves BWI Rail Station is the MARC Penn Line/Amtrak Northeast Corridor, which can only take you to Baltimore Penn Station downtown, from which you'd have to backtrack by light rail or taxi. Should your plans take you to Washington, however, the MARC Camden Line can take you from Camden Yards to Union Station and back.