I have been pulling a fiver for over 20 years now and have never came across a low bridge yet. I drive a semi and minimum height for a trailer is 13'6". If you do come to a area with a low bridge there should be posted signs way before you get there. I know there are places with low bridges but I have never been there. I don't see it being to much of a problem, just keep your eyes open for signs. My biggest fear is gas stations. there are a lot with low over head roofs that are low enough to take out the A.C. on the trailer roof, just be careful of them. I always stay to the outside pump for them.