Originally posted by Foley:
What area are you trying to go to in the Washington area? If you are going to DC itself, I would recomend DCA as the cab fare from IAD to downtown will run you about $50. Also, depending on what time you arrive, some of the main access roads to DC are restricted to vehicles with two or more passengers. Stiff fine if you are caught with only one person in the car also ($500).
The "HOV" rule does not apply if you are going to/from IAD on the main highway (I-66).