You need a CDL to drive a semi on a public roadway.

 

If it's plated as a recreational vehicle and operated only in that capacity, and is operated solely for personal use, it falls outside the jurisdiction of FMCSA and doesn't require a CDL.
Farm vehicles are exempted within a certain radius of the farm they belong to, so long as they meet certain guidelines.
I was delivering sod in a registered farm truck.. Class 8 tractor and 45x96 trailer with a Donkey on the back.. before I ever got a CDL, and it was all legal. Didn't have to upgrade my license at all, although I did have to keep a DOT medical card. I couldn't travel beyond 100 road miles/150 air miles of the farm, and I had to be a direct (W2) employee of the farmer in order to be able to do this.

 

Interesting read. I drove farm for years ( owned a horse ranch for a while ) and got away with murder. The range from base isn't an issue as the rules say you can be traveling between properties and you don't have to own both of them. farm plates are awesome.

There was an issue of air quality regs and older trucks brought up. Any lively reading on that in here somewhere ? I'm guilty of being interested in an older long nose Pete with a med to short wheel base for hauling a land yacht. But it needs to pass Weld county Colorado emissions. I think, whats the scoop on what emissions these things need to pass