It's awkwardly worded, but the "other motor vehicles" presumably refers to the "No motor vehicle", etc., so I think the second sentence intentionally carves out an exception from the first. The implication seems to be that before 1980, state or local governments designated some areas within the jurisdiction of the Pinelands Commission for off-roading, and these are still OK to off-road on, BUT the Pinelands Commission has the power to take some of them out-of-bounds for off-roading.Hmmmm
"No motor vehicle other than fire, police or emergency vehicles or those vehicles used for the administration or maintenance of any public land shall be operated upon publicly owned land within the Pinelands."
"Other motor vehicles may operate on public lands for recreational purposes on public highways and areas on land designated prior to August 8, 1980 for such use by state and local governmental entities until designated as inappropriate for such use.."
Aren't these statements contradictory?
What exactly was designated as public highways and areas on land upon which vehicles can be operated recreationally?
I'm ignorant of the history here, so I don't know what areas these would be. Presumably that corresponds to the "areas for authorized ORV use" in the DEP policy statement at https://www.nj.gov/dep/commissioner/policy/orvpolicy.htm.