Not a massive trip by any means---1500 miles round-trip, which is definitely shorter than my trip to Connecticut last year. Also, as far as traveling goes (and I'm an interstate traveler, I waste no time with offroads), you're basically on the same road for the entire journey.
Hard to imagine that covered 730 miles. Mainly, it was I-81, which apparently goes on and on (I took the exact same journey on my Connecticut trip last year), so I definitely appreciate that.
Starting in Nashville, the ground is mostly flat--and of course once you get to the eastern part of the state, you start seeing the warning signs for tunnels (!!!) and down-grades in terms of how steep the mountain is. This probably won't affect seasoned drivers, and definitely not the locals who speed around the corners then amazingly forget about the Cop cars lurking around the corner. The last time I tripped up this interstate, I hated my time in Virginia. I-81 N basically goes parallel with the border of Kentucky, so you're going into and out of Virginia at a very odd angle, which makes for a lengthy trip. This time, I enjoyed it. I set myself mini-goals like no bathroom/gas breaks until Roanoke, until Winchester, etc. And you really just don't want to stop on your brief visits into West Virginia and Maryland. Once in Pennsylvania, I was home free. Thank you, Hampton Inn.
I'm not exactly how big the town of Harrisburg is. It's looks a decent size until you get there and then I think I was too far on the East to catch much. I ventured out of my hotel and wound up in a sketchy neighborhood. The streets get smaller, cars line both directions (not in traffic, but in parking)--the houses are about three-stories tall and smashed up against one another. It was beautiful in a kind of I've-seen-this-in-History-books sort of way, but the further on down the street I got the less inhabited it became and the more graffiti lined what was probably a really awesome place (back in some day).
What Harrisburg is close to is...Hershey, Pa! Home of chocolate! I didn't really venture into the theme park (I was there for a concert at Hershey stadium), but Chocolate World was pretty cool. Very cliche chocolate. Went on a small tour (10-minutes or so) about how chocolate goes from the cacoa or cocoa bean into the chocolate bars and kisses we see today. Pretty interesting. Got a free S'more bar after that (by the way, the whole tour is free). There were many stores downstairs carrying every kind of chocolate you can imagine in a million different sizes; also regular food for us regular people with stomachs. Also, Hershey stadium was okay. Be careful for any concert-goers, the stage is about 10 feet high.
On my way back to Nashville, I mistook I-83 for I-81 and ended up in Baltimore, Maryland. Not a huge detour, but I was definitely thankful to have my updated 2004 Atlas! It took some time, but I navigated myself back over to I-81 as opposed to driving to Washington DC and then hitting I-71 (or 77, something like that). This time, the drive was long--it always is when you really just want to be at home. I was also sick which can speak for the type of driving you like to do. This trip, I traveled alone--I do these every now and then to clear my head. Being sick, I had to pull-over at weird gas stations and sneak naps which added to my time. Nonetheless, the road was the same, the whole way. Usual traffic in Knoxville.
Oh, on my detour--there are just some beautiful places to be seen between Baltimore and Charles Town, West Virginia. Gorgeous. Entering West-Virginia from that angle makes you feel like you're just driving through a forest and maybe you should pull over and camp. It was very surreal.
Overall good trip; could've had better weather (rain both ways; though it was sunny on the day of the concert, so I probably shouldn't ask for more) :)