The 5A stops at Herndon and often at Tysons/Westpark as well. I don't mean this as a nitpick; it's relevant because a direct trip from Rosslyn to Dulles could t

The 5A stops at Herndon and often at Tysons/Westpark as well. I don't mean this as a nitpick; it's relevant because a direct trip from Rosslyn to Dulles could take the airport lanes on the toll road all the way from the 66/267 split, but the additional stops mean the bus can't take advantage of the airport lanes, making for a painfully slow trip. I've done it a few times, and it's just not practical if one is travelling for business and at all pressed for time. National on the other hand is a downright pleasure to fly out of. I go through National once every week or two and Dulles every month or so. Parking, security lines, and everything else are so much better at National.