In other words, like most people with statements like this, you don't have a link.
I don't believe that ANY state requires an RV to scale.
Here smart azz,
Maryland Motor Carrier Frequently Asked Questions. Pay special attention to section 5 and 8. It doesnt matter if you have an RV or a truck full of unicorns, over 10k and you have to weigh.
5. What is the definition of a commercial vehicle?
The Federal Motor Carrier Safety Regulations have defined a commercial motor vehicle (CMV) as noted below. Maryland has adopted this definition for commercial vehicles that operate only within state boundaries (intrastate).
CMV definition:
Commercial motor vehicle means any vehicle operated in interstate commerce to transport passengers or property when the vehicle
(1) Has a gross vehicle weight rating or gross combination weight rating, or gross vehicle weight or gross combination weight, of 10,001 pounds or more, whichever is greater; or
(2) Is designed or used to transport more than 8 passengers (including the driver) for compensation; or
(3) Is designed or used to transport more than 15 passengers, including the driver, and is not used to transport passengers for compensation; or
(4) Is used in transporting hazardous?materials?in a quantity requiring placarding.
8. What vehicles must go through weigh stations in Maryland?
All vehicles with a gross vehicle weight or gross vehicle weight rating of greater than 10,000 pounds must stop at open weigh stations. Only vehicles that are operating in commerce will be subject to a safety inspection.
9. Does a rental truck hauling personal property have to stop at weigh stations?
Yes, if it weighs more than 10,000 pounds. However, these vehicles will not be subject to a safety inspection.
Happy? Why dont YOU do some searching next time before running your mouth.