In those units, travel is limited to roads accessible by full sized automobiles. However, under the definition of that full sized car, it specifies that it's anything over 1500lb. There are lots of UTV's out there that weigh more than that. At the same time, while a UTV can be used on about any road anywhere, you still can't shoot from it. You have to get out and get off of the road.

Quote
It is Unlawful To:
Hunt big game or game birds from or by the use of any motorized vehicle, including any unmanned aircraft system (drone).

“In a time of deceit telling the truth is a revolutionary act.”
― George Orwell

It's not over when you lose. It's over when you quit.