>Why hasn't a developer figured a convenient one way in and one way out method of parking yet?
Check out the Target in Herndon where the parkway crosses Sunset Hills. It's freaking genius:
https://www.google.com/maps/@38.9543967,-77.3687979,129m/data=!3m1!1e3
Entering traffic has a couple of ways into the lot with the first entrance heavily favored, but exiting traffic is all routed to the south edge of the lot because of the median on the entrance road.
As for the Price Club Home Depot, never use the eastern entrance to leave the parking lot. If you are picking up a lot of shit and need to park in front of the store, then drive around the building to get out. There is always a path through the back alley because they take deliveries. If staff are working their forklifts, it's never blocked for more than a few minutes at a time.
Just forget about Merrifield Home Depot. That garage is a nightmare.