Originally Posted by
crhptic
Getting from IAD to downtown DC is only marginally faster than getting from BWI to downtown DC.
Not if you're taking the B30. MARC can be faster if your flight arrives on time and you're not waiting for the bus to schlep you over to the station. (Well, the last time I took MARC they cancelled one train, causing me to wait an extra 40 minutes--but that usually doesn't happen!)
Another thing to factor in, if you arrive later than scheduled and miss the last train or bus: Cab fare from IAD is a lot cheaper than from BWI
to downtown D.C. too.