Originally Posted by inlogan
The B30 isn't a shuttle. It's a regular WMATA Metrobus from the Greenbelt Metro station $3 each way. The shuttle from the BWI Rail Station is free and runs on the weekdays every 15 minutes or so, but I'm not sure about the weekends since the MARC train isn't running. Are you planning to take Amtrak from Union Station to BWI, or are you planning to take Metrorail to Greenbelt and then the B30 Metrobus?
Metrorail to the B30 will take an exorbitant amount of time so I'm planning on taking Amtrak to BWI and using the free shuttle bus. This will be on a Sunday. My flight leaves BWI at 2:30pm and I'll already be checked in for my flight with only carryon. Can I assume a 12:25pm train from Union station will get me there with enough time? By my calculation I should be arriving at security over an hour before flight time.