Not sure of all the rules and regs. That was the reason that I put the question mark. However, still see a lot of trailers going up and down the road with just the flat 4 pin connectors. OR, nothing connected at all.

The equipment rental companies around here are starting to rent the 10K-14K dump trailers. Waiting for some yahoo to load one of those up behind a half ton truck and pile it up. Some of these guys have never pulled anything bigger than their little red wagon. Buy a new truck, and then think they can drive / tow / trailer as well as a 40 year OTR driver...