OL couse, the first thing which came to my mind is US-6 through PA. Buck beat me to it. A wonderful route with great hikes including in Kinzua SP and the Grand Canyon of PA. Don't miss all the murals made from old road signs, west of Warren. Even continuing on US-6 along the south shore of the Lakes, there are many SP and other scenic places to pull off andenjoy, as well as camping spots..... if you can make your way through Cleveland.
Further south, as well as US-30, there is US-20, along which rthere are some interesting places (as there are along most of the US highways) and aklso takes you through Amish country.
If you are into railway history at all, you may be interested in taking a short detour to Nicholson PA for the Tunkhannock Railway Viaduct. You can actually climb to the top and walk on the track.
Lifey