Drove past a weigh station a couple of weeks ago and saw a U-Haul truck waiting its turn.... If this is a new requirement, it's an excellent one and one that has superb potential in many ways.
I think it is one of two thing. Generally Uhauls are exempt from these stations because their cargo weight doesn't meet the regulatable levels and secondly, they are non-commercial. However, companies sometimes rent these types of vehicles to suppliment their capabilities (watch Fedex and others this holiday season), in which case they must be monitored and permitted as required.