Well I drive a truck hauling petroleum coke out of the Conoco Phillips refinery as a regular job and am doing this on the side. I've had a class A CDL for about 5 years and drove over the road after I went out of business before I landed the home every night driving job that I have now so I'm pretty familiar with the FMCSR's and ODOT regs. You're correct, DOT usually goes off your declared GVWR (sticker weight). There are also bridge laws that come into play. Contrary to the name "bridge" people often think of an actual bridge. But these laws refer to the length from one axle to another. Say you have a declared WR of 80,000 but you're pulling a rock trailer that isn't long enough to "bridge out" 80,000, you may only be able to haul 74,000 lbs. Bridge laws are a pain in the butt when it comes to trucking. As you said though, DOT usually goes off your door sticker. For example, your tractor trailer that has a declared WR of 80,000 lbs but when it's empty only has a tare weight of say 29,500. If you get caught taking a short cut on a road that has a weight limit of 25 tons (50,000 lbs) you can still get an overweight ticket, even though you're rig is not loaded and weighs 29,500. Like you said, they look at your declared WR. As far as my 12' landscape trailer goes, I'm not sure if I understand your question. I can tell you that the axle on my trailer is a 3500 lb axle. You are correct if you are asking if that is GVWR. Meaning, the 3500 lbs consists of the total weight of the trailer, not just the payload. By payload I mean all of the equipment you put on it or mulch, sod, etc. Total weight shouldn't exceed the 3500 lbs if you were to weigh it on a scale. I'm able to put around 2,000 lbs payload on this particular trailer. My mower and hand helds don't come to that, so I have no need for a heavier axle like you might. When I was in this business full-time I had several tandem 16 footers and a 20' trailer too. It's nice having the ability to haul more, but since I'm just coming back part time and all I do is maintenance I chose to go with a 12' single axle. I hope I answered your question. Does DOT bother landscapers in your area? I know they don't really mess with us around here if you're just dragging around a bumper pull. Going across state lines on interstates is always a risk, as there are usually port of entries that might hassle you but for the most part they don't mess with people who are running around town cutting grass. Always remember though, if you're overloaded and have an accident, you're opening the door for a lawsuit.