http://www.washfly.com/metro.htm has info. Under "Location" there is a map on where to find it at IAD. The coach takes you the West Falls Church (WFC) metro stop. Where you get dropped off is where it picks you up too. The WFC metro stop is on the Orange line. You want to take the line going toward New Carrlton if you are heading to DC. If you are heading toward Dulles Airport then you take the Orange line toward Vienna and just get off at WFC.