Just for the record - the orange triangle low speed vehicle sign (which I've NEVER seen on a 4-wheeler) is required for vehicles moving less than some speed dictated by the state. Here in Idaho it's 35 mph which is probably fairly standard.
If you driving a LSV on a public road, you must have a valid drivers license.
And you must have the same minimum liability insurance as required for regular vehicles. I suspect the insurance is regularly ignored but if a cop pulls you over for some reason, I'll bet he won't ignore it.
