OK, that makes sense. First time getting off around there since we're staying in Falls Church off of US 50 and the three times through on 50 so far have been in the dark. So, I didn't pick up on the difference between it and US 29 (just through once so far). Some of the map overlays do not make it as obvious as Google Maps does. Thanks for the explanation. I'm cool with I-495 as our waypoint for US 29, although I'll see if we can extend it as we head out of town tomorrow. Otherwise, a future trip.
Mike