Not sure of your location but if your in the NY/NJ area... the NY/NJ Trail Conference has some of the best maps I have seen, aside from being pinpoint accurate about the trails – each of the maps the parking areas are labeled. Most are actual parking "lots" but some are just pull offs from the road.

Haver you thought about leaving a note on your dashboard saying you are a hiker ( though it may not prevent a ticket, but it may give peace of mind).