Originally Posted by
mhnadel
Best route is likely Dulles Access Road to the Beltway to Clara Barton Parkway, exit Reservoir Road and wind around to Q Street from there. A taxi driver presumably has an advantage over me in being less likely to make a wrong turn along the way, but given a few taxi experiences I've had here, I wouldn't count on it.
Clara Barton Parkway is one way (outbound from Downtown) during afternoon rush hour. So that is a no go. GW is your alternate to I-66.