I have driven I-81 many times in the past, and Montana highways recently, that said, I-81 in Va and Pa scared the crap out of me because of the tractor-trailers that dominate the road. They show no mercy and band together in convoys, God help you if you get in their way. My wife and I even reported one trucker who was running people off the road, and the State patrol’s reaction was “ho hum”. Montana, on the other hand, had all these little crosses at scenes of fatal accidents, which had a sobering effect.
Now, if we talk about most of I-95 from DC north to the NYC area, then I've got too many horror stories to tell.
All the best to you!