Where was planes trains and automobiles filmed?

Answer 1

There were several locations in the film but a few outside shots were taken in Gurnee, Illinois (that's outside Chicago) at The River Trail Gardens and Inn located at 36355 Route 41, Gurnee, IL, 60031. It's a motel they used in (I think) that scene where Steve Martin and John Candy have to share a bed? The building doesn't really look the same anymore but you can go see it!