It has nothing to do with lighting, equipment on board or having a sprayer in the back. It has to do with the definition of the type of vehicle and how it is registered. If it is registered as a UTV, you can spend hundreds of dollars on turn signals and other equipment, but your UTV is registered (or should be) through the DNR and not the DOT...because a UTV does not meet the requirements / definition to be operated on the road unless ATV/UTV ordinances are adopted by the township. Yeah, you could throw a sprayer in the back and carry a shovel or rake, but keep in mind if you are stopped and get caught in that lie, the consequences are going to be pretty stiff...Remember, law enforcement officers in those rural areas are pretty familiar with the local farmers and property owners. They patrol those roads daily, many for years on end...they have more than likely assisted them with rounding up loose livestock, provided light coverage for broken down machinery, dealt with trespassing issues, etc. I'm not going to say you WON'T get away with it, but the deck is not stacked in your favor...to me, it isn't worth it just to ride my ATV to the bar or store.
My township passed ordinances allowing ATVs and UTVs on township roads and there have been multiple serious injury and fatal accidents as a result. They were not meant to be driven at high speeds and were not designed with sufficient lighting to be driven on roadways (heck, my Honda Rancher has a tail light, but not a brake light that gets brighter when you brake!?). They have very soft suspensions, low pressure tires and any evasive maneuvers (swerving to avoid deer or a collision with another vehicle) often lead loss of control and/or rollovers. Then there are the people (like with vehicles and motorcycles) that refuse to wear their seatbelts and don't wear helmets or other safety gear and it is a recipe for disaster. You stand no chance against another vehicle traveling at highway speeds. These are my opinions and experiences, your mileage may vary.