I've had this happen on a variety of concrete highways. Even a brand new one just a few months old, and it was the worst I have ever seen. When the concrete drys it sometimes "cups" a bit. The high points are at the expansion joints. This causes the problem. It has nothing to do with truck, trailer, or tongue weights (unless too light). Having the WD hitch adjusted properly and the correct tongue weight will help. The most successful fixes to this problem is to install shocks on the trailer or a product like the
Lippert equa-flex. The equa-flex (and others)is designed specifically to reduce the problem.
