Those are not rest areas. They are roadside tables, sometimes referred to as roadside picnic tables.
A rest area has "restrooms". It may be a portable one that gets swapped out once a quarter, or it may have flush plumbing (that may or may not work). Decent rest areas also have spaces for truckers to pull into where they can, you know, rest. (I hear that's what they call it when they are adjusting their logbooks.) (For some values of rest area, I hear that "adjusting their logbook" is what they call other commercial activity.)
Rest areas and some roadside table locations seem to be one of the last bastions of the pay telephone. Well, those and certain concentrated urban housing developments despite the availability of cellular phones.
stay safe.