The Washington Flyer Coach fare goes up to $10 on 7/1/08. And you can use a credit card for it. The bus leaves from the Arrivals Level (up the inside ramp opposite Baggage Carousel 8) at door 4 . Tickets are sold in the vestibule just inside door 4 and bus is right there.

The 5A Metrobus is $3.10 cash fare - the driver does not make change. The 5A leaves from Curb 2E of the Ground Transportation road (down the inside ramp opposite Baggage Carousel 8), where you see the Car Rental shuttles.