Not knowing your history Lou, have you traveled in European or Asian countries much? Tractors on the hiway is very common. Sometimes it's the means of transportation, nothing to do with tractor tasks. Cabless tractors will have a mirror clamped to the vertical exhaust. Seating platforms fastened across the rear fenders. Very common to have hiway speeds in the high 30s or low 40s.
The more developed nations have comprehensive laws in place to control this use just as they do for cars/trucks. The Auto drivers tend to accept the tractors on the road better than we do. We only consider them a distraction.
Europe no, Southeast Asia yep.
I have followed some of the European tractor regulations as at times various bureaucracies in different states have attempted to shove some similar regulation down our throats.
Anyone who believes that it would be just a minor inconvenience and a minimal expense to keep fully functional lighting on a multitude of farm equipment has absolutely no idea of what would be involved. Much of the equipment in use today especially on the smaller farms and even many of the larger ones is well over 20 years old.
Many of the older tractors do not and have never had anything beyond a flashing lamp mounted on the left fender,
no directionals, 4 way flashers, or even headlamps.
At this time in this state the only thing required in daylight hours is a SMV sign.
I certainly don't consider nations to be more developed because they have more regulations and controls on people.
And as a footnote drivers better accept me on the road with 20-30,000 pounds of tractor, pulling a chopper of a few thousand pounds and a self unloading wagon,
which when empty going to the field is only a couple of thousand pounds but when I'm headed home with my last load of the day another 5-7 tons of silage.
Because I may max out at 15-18 mph and slow down on hills because I've only got 220-250 hp to work with. And I do take up most of our secondary roads.
Oh also those tractors with that high speed are not pulling a heavy load up any kind of grade.