Yep, the people that enforce the law are just as confused as we are.
Exactly.
What it amounts to is USDOT trying to get involved in nation-wide mandates, which should never have happened in the first place. But until every state either conforms to a widely-accepted definition, or establishes reciprocity with other states, the problems are going to continue.
Basically, if everything is rated for 26,001 lbs. or more, or if you are using the vehicle/s as part of a commercial venture, then it's better to be safe than sorry. But that suddenly brings in all of the medical card hassle, all of the liability insurance hassles, all the logging hassles, time restriction hassles, etc. With all the wee surprises that come along, as part and parcel of the overall scheme of things. Here's an example. Most states recognize .08 BAC as the legal definition of impaired driving. But, if you are driving a truck/trailer combination that requires you to be licensed for commercial motor vehicles, .04 BAC is suddenly the number used.
And remember, there are some situations where you would not be required to hold a CDL, yet you would need USDOT registration and display. Some states will require USDOT if you drive beyond a certain radius of your home, and some states will require it if you intend to drive over state lines.
And if you think this all sounds like a lot of heartache, try towing that same rig over the border into Canada.
The inspection lots at border crossings can be very grim places, in the wee hours of the morning. Been there, done that. I remember a woman from U.S. Customs running her hands behind spare wheels and tires mounted on the trailer walls and even sifting through a rubbish container in the trailer. Some of them conduct inspections with respect and some of them are sadistic.
