Its not that bad unless you're looking to challenge someone's corner in their 'hood.
If there are museums or sights you want to see, you'll be fine as long. Like anywhere, pay attention to your surroundings.
And don't carry loaded gun in NY, Del. Md, or Pa either without a permit.
Haven't responded with suggestions because not sure what your goals are. nature? history? cars? racing?
If you want to hit the big cities, your going to be on the coastal areas. You want to make time, you'll use I-95 and it's 'ring roads'. If you want to sightsee the country, then older US routes are sometimes a good alternative.
If you go further inland, it will be a bit cooler. A bit.
In Eastern Pennsylvania there is an automotive museum in Allentown "Wheels of America", a transportation museum near Reading - maybe its in Boyertown, and the Simone Foundation Racing Sports Car museum near the Philadelphia Airport.
