We had instances of that last year in Indy, on the Monon Trail. Commuters caught on it after dark, in the fall, when sunset was creeping earlier and earlier. Signs say "dawn to dusk", but the local bike advocacy groups rallied the Mayor's office to reverse the tickets as the cyclists were commuters.

Here the trails are part of the city park system and are considered "parks", so their standard "dawn to dusk" rules apply. Not sure where the funding came from to build them however.