I think jwhouk is getting what I mean. There's a big difference between "scenic views" and "road & trees". I love nature. When we drive from NJ to VT, my favorite part of the 5 hour drive is the last hour looking at the mountain range in southern Vermont.
Let me explain my reasoning another way: 11 years ago, the friend that was responsible for introducing my husband and I (a mutual friend of him and my ex), graduated college in Arizona, and was then moving back to NY. Since he had to drive back all his stuff, I suggested to Mr. Z that we fly out to AZ and help him drive back. My ulterior motive was at that time, except for a flight out to Iowa to visit some family, I had never been anywhere in the US except the East Coast. What I found out too late is that they planned the drive for the same week my husband had to be back for a mid-term, and the guy had to be in a wedding in NY. So ended up driving, non-stop except for gas and an occasional pee break, all the way back. 10 states we drove through, and what did I get to see? Nothing. Hundreds and hundreds of miles of nothing. (Okay, not entirely true: I got to see the St. Louis arch from a distance.) The route, though the most direct, had nothing to look at past New Mexico. Literally, the only thing I saw besides dirt in Northern Texas was a giant white cross in the middle of nowhere. It was the most boring, bland stretch of road I've ever been on. The "scenery" was non-descript. I almost crashed once because I started falling asleep at the wheel.
The point being, even if it takes longer, look up a route with places to stop and things to see. (I'm not talking about shopping malls and fast food.) If you're taking the route Google suggests from DC to Niagara, I can tell you from experience, because I have family in Hagerstown, MD and central PA, there is nothing but road and trees for a good majority of that trip. It's not really too scenic, and you can go an hour in between exits. Although, if you're a fan of the Civil War, there are some really neat battle sites to visit out that way.