When stopped by Vehicle Enforcement they will simply use portable scales under the trailer axles. Whatever the reading is better not exceed the trailers weight rating....but again, that figure is open to interpretation. Is it the the combination of the axles rating or the trailer rating? Depends on the LEO to be honest. In some states they don't even consider the axle rating...thats a fact. They simply weight the gross (truck, trailler and load) and compare it to your plated weight.
Because it generates more revenue for the states, make sure the plated weight of your truck isn't exceeded by your gross. In some states, thats the first thing they look for because not only do you get the citation for axle weight, but now you have to go downtown and increase the plated weight on your tow vehicle and the state gets more $$$$ yearly.
so, you could have a load of only 9,000lbs on a trailer AND axles rated for 12,000lbs+ but be overweight because the truck is plated (registered) for only 8,000lbs.
There isn't any one source to determine each states regulations...I wish there were, it would make my job a lot easier. Do yourself a favor and contact each states VE division.
Anyone claiming to know each states regulations and enforcement for motor carriers is fooling themselves.
