Overnight at New Jersey turnpike rest area

I can't swear to it but something tells me I have seen some hourly parking limit at rest areas on New Jersey Turnpike. I can say that many of my long-haul truck driving friends spend the night regularly and no one bothers them. Keep in mind many of the rest areas are absolutely full of tractor-trailers at night. Many of them are idling continuously, and many are parked along the entrances and exits of the rest area due to overcrowding.