Oh, and before I am considered an "expert", most of what I say here can be found in the pdf file linked elsewhere in this thread. I've been looking at this UCR thing for a year now.  I finally broke down and applied for a UCR even though I personally do not think I need to, because interpretations of the law by the courts seem to think I do.

It is a paperwork violation.  5 years down the road some auditor can go "Let's see, in 2010 you delivered grain to ABC elevator who was on a railroad and could be expected to ship it interstate and you didn't have a UCR.  You fine will be ..."

You think I'm overstating it?  Ask my friend whose business diligently paid sales tax on sales in Indiana for 25 years, but (even though over that time had 3 different accounting firms doing their taxes) never filed an Indiana income tax form.  The experts said he was based in and operated out of Illinois so it wasn't required.  Indiana went after him for back taxes on 25 years of sales in Indiana.  It was all a paperwork violation.

For purposes of the UCR and the USDOT# registration, a commercial vehicle has a gross vehicle weight rating (GVWR) of at least 10,001 pounds or transports hazardous materials in a quantity that requires the vehicle to be placarded.  For purposes of the UCR and the USDOT#, a farm truck is considered “commercial” generally based on its size—if it is over 10,000 pounds GVWR or a combination vehicle (truck & trailer) with a GCWR over 10,000 pounds. And the minute you hook on to an anhydrous wagon, pull a diesel tank over 110 gallons, or throw in enough insecticide to require placarding you qualify.

As I understand it (that is a warning!) the weight may be actual weight or legal capacity.  I'm a bit fuzzy on this because I've heard it both ways. if the GVW on the vehicle data plate or the weight rating on the license plates is over 10,000 then USDOT is required.  let's say you have a pickup and a gooseneck trailer each weighing 4999 pounds.  As soon as you put 3 pounds on the trailer you are over the line. OR (as I have heard some interpret it) if the license plates for the truck are 8000 and the lawn mower trailer behind it are for 3000, you are over 10,000 and qualify.

It gets better.  If it is probable (probable is a key word. It doesn't have to happen, it just has to be probable) that the grain a farmer delivers to a location in Illinois will ultimately be delivered out of state, then it a UCR is required.  The USDOT# is the federal identification. The UCR is a fee collection system. If you need UCR, you’ll also need the USDOT#. In fact, you will be required to have the USDOT# before registering for the UCR.

The USDOT# registration requires that the commercial vehicles be marked with the legal name, or a single trade name, of the business entity that owns or controls the motor carrier operation. City and state are not required, but allowed.  So if you have to have a UCR (and unless it is probable everything you haul may not be shipped interstate you need one) you have to have a USDOT# which means you have to have you name and USDOT# on the door.  Technically the legal name on the title of the vehicle.

More fuzzy area.  If the USDOT# is for Robert Jones but the title has Robert and Gloria Jones ... does Gloria need a USDOT #?  Or does the R & G entity need it's own USDOT# ?  And putting Jones Farm on the door with Bob owning a truck and son Bill owning a truck ... both need USDOT and UCR numbers.  This gets awful uncomfortable really quickly.

Oh, and while we are pondering on all this, think about grain carts and wagons.  A farm wagon weighing up to 36,000# GVW is considered to be an “implement of husbandry.” State regulators are not imposing UCR or USDOT# registration requirements on implements of husbandry (i.e.: farm tractor pulling wagon.) If the tractor and cart weigh over 36,000 we're in a fuzzy area again.  But if the grain cart by itself weighs over 36,000 it is over the line and subject to all kinds of stuff that will ruin your day.  About the time you run a 750 bushel cart over portable scales and the dollar signs start rolling in some DOT guys eyes ... really bad day.

I heard an Indiana DOT guy talking about it a couple years ago.  He said there was going to be a big blow up over grain carts some day when a farmer got caught with his 750 bushel cart loaded going down the highway.

And trucks pulling wagons could be regulated. The wagon is an implement of husbandry on a tractor.  Pull it with a truck and it may need license plates.  And if the truck and wagon together weigh over 10,000 pounds ... I recall that number form someplace.

A lot of people are not going to be happy over this UCR thing, but there is no way around it.  The only way I see around it (as I understand it right now) is if you haul everything to your bin and someone else hauls it all out.  Maybe you can get by.  Or if everything you grow goes to an ethanol plant, feed processor, or soybean processor.