Transportation from BWI to DC
 

Without renting a car, what's my best bet for getting from BWI to DC, and from DC to Baltimore for an Orioles game and back again?

MARC or Amtrak works for both, depending on the hours of travel. There are cheaper options, like a bus to some stop on the DC metro line outskirts but I know little about that.

You can take a shuttle to the BWI train station and take Amtrak into DC or for a lot less money, you can catch a bus (someone else will hopefully have the #) to the metro station and then metro into town.

As far as going to the ballgame, that'd be AmTrak or MARC trains from Union Station to Baltimore.

Enjoy your trip.

MARC vs. Amtrak:

MARC is cheaper, not as comfortable, and doesn't run on weekends.

How does MARC work? where do I pick it up at BWI? Where does it take me in DC?
THanks for your help.

Don't have the bus number but it's a Metrobus from BWI to Greenbelt Metro Station. It's a very good and cheap option. http://www.wmata.com should have info.

At the same BWI station as Amtrak for pickup and the destination is probably still Union Station (I think both also stop at New Carrollton which is a metro stop) -- MARC is the maryland commuter train versus AmTrak that goes up/down the east coast. The cost difference can be significant, if the Amtrak is a metroliner or acela (don't know if the latter stops at bwi or not)

And you can buy tickets for the MARC train at the BWI rail station assuming you wish to go on a weekday. If your game is a night game, check the MARC schedule to make sure that the trains will be running that late after the game.

Danger alert! The BWI-DC plan is fine, but the train to the ballgame may have a very serious flaw. A couple of years ago, the geniuses who schedule the train eliminated the post-game return run to DC. Check to see if there's a way to get home before setting out.