Then there are these monstrosities. I followed one of these TowPlows this morning for a few miles on I-80. Long and wide. It will plow a swath 25 feet wide at highway speeds. During it's quick conversion from a trailer to a plow (or visa-versa) it looks like it's jackknifing- technically it is but it really looks freaky the first time you see it happen. Impressive machines. Iowa DOT purchased 3 of them.
I had to Google the thing after I saw it. The wheels on the trailer turn 30 degrees. Pretty quickly too. When it does it looks like bad things are about to happen. Yes, it is remote control from a console that looks more like a cockpit.