I've used our Magellan Roadmate RV9490T-LMB the last couple of trips down and back. I like to take 75 to 10 (not a fan of 4) to 95 until the tunnel in Baltimore. This is where I've nearly thrown the...
We stopped using 95 around the capital years ago. The 301 route is much more scenic and enjoyable. North bound pick it up in Virginia Exit 104. A flying J on both sides of of 95. Prefer the one on the west side for RV ingress and egress. As others have said 495 and 695 will get you around and avoid the propane restrictions in the tunnel.