I really enjoyed this FKT. I started as Greg did from the Ronald Reagan statue at Terminal A at DCA airport and followed the "google walking directions" to Washington Dulles (IAD).
This route was a bit complicated and as a local I found that strange at points but overall it was pretty good.
I did this unsupported and used just one bottle of fluids and one GU, so pretty pumped about that as was a nice test of fitness.
I started a little after 6:30am and the weather was so nice, about high 40ties and crept up to mid 60ties.
I loved being out there and for the most part the route was pretty straight forward except the last 5 miles from the W&O rail trail to Dulles airport. That was not nice or that much fun getting to Dulles but once on the airport property it was really cool and I always love seeing the terminal at Dulles.
I would recommend this route and think it could be great and faster to go from Dulles (IAD) and Reagan (DCA).
I think could be neat to add in BWI and we can get an even bigger run..wink.