So is Amtrak the only way on the weekend? My son is going to be in DC for his junior year of high school and we are looking at ways to get him home for some weekends. BWI fares are much cheaper, but more complicated on the ground. DCA is easiest as he is living on Capitol Hill, but fewer flight choices. He's a great traveler and intrepid about glitches, but with so little time off, we do want to mimimize his travel time to give him maximum time at home.

So in instances where BWI is the flight option, walk to Union Station, MARC to BWI on Friday, Amtrak to Union Station on Sunday?