I can't remember the name of a road trip move from the 80s maybe early 90s.

The story is about a guy taking a brainy girl on a road trip to a college interview in a certain amount of time.

I remember a scene where they are stuck behind a tractor trailer with a sports car riding their bumper. They are all going slow because in front of the trailer is cop so the guy slows down his car so the sports car passes them to get caught by the cop so the trailer can go fast again.

Any help would be great, thanks.