My buddy was just telling me that if you are doing commercial work (or looks commercial according to the Weigh Station police), you have to have a DOT number and a Chaufers license if your vehicle has a combined gross weight of 10,000 pounds.
I don't know if this is accurate or not, but thought I mention it. There are some other regs he told me, since it didn't apply to me, it just kinda went in one ear and out the other.