Interstate 10 weigh stations in North Florida frequently have portable signs displaying the message:
"ALL TRUCKS, ALL TRAILERS, ALL RENTAL TRUCKS, ALL RENTAL TRAILERS, ALL PICKUPS MUST ENTER WEIGH STATION". Not so much for weight as for other issues such as immigration and untaxed fuel use if you have a diesel engine.
If you are transporting a rig for hire from the factory to the dealer, you must keep log books, have a commercial drivers license and medical certificate, and stop at all weigh stations.