TO a very great extent it depends on when you are traveling.
Example: Next weekend is memorial day.. July 4, Labor day.. All busy days
This weekend within 50 miles of Xenia, OH.. Very busy (I just got back from Xenia) In fact I was unable to get a reservation for the full weekend. (Changed when I got here and down-graded my site needs.. NOTE: Not a hardship at all.. I don't need sewer for this short a stay)
OH, The main crossroads in Xenia in the morning.. Forget it, parking lot, as thousands of folks like me descend on the fairgrounds.
(I had a very good day there today. Beat most of the traffic because I had a plan that worked very well.. Got everything I wanted to do done, Spent the money I planned to spend. Very happy.)
For fellow Ham Radio Operators reading this.. As I said, for most traffic was a witch. Thanks to good maps and a willingness to "Adventure" and my plan (Eat breakfast in Xenia was the plan by the way... Linda's Cafe, about half a block east of Detroit on the south side of Main) Dinner too. The specials this evenign were 3 for 3 on my favorites list) I avoided most of the traffic jam.
The fairgrounds layout was fantastic.. I got to EVERY exhibitor's booth, Ever Flea Market spot. And more... NO problems, all in one day. WIth the old arena you got lost more than anything.