Hm, they've been caught before for trying to do something illegal; they are not allowed to give any form of discounts as a turnpike on the federal highway system. (To prevent perverting the cost structures to in-state user's advantage.)

Are they not going to charge fees for these paper bills when paid on time? Can one pay one in cash and without needing a stamp? Even if they've sorted those two out, a third of people not paying and that being made up in fines makes it sound onerous which is against the spirit of the rules.