The 30 mph has been around for several years on larger lakes. Some guys I know with "lead hands" have quit fishing night tournaments because of getting several speeding tickets on Table Rock. They don't have to spend much fuel just run a radar gun at a confluence area.
I don't mind the 30 because my boat will plane at 25 mph so 30 is ok. It gives me time to look around at shore lines and keep my eye on the sonar and gps units. In my experience, most of the people on the waters where I fish are running close to the speed limit at night. Of course all of God's little creatures don't have common sense and I don't go to LOZ.