N.J. Stat. § 27:19-13
The board of chosen freeholders shall make rules and regulations for the protection and use of the viaducts and bridges in the county under its care and control, and may place any viaduct or bridge in the special care or charge of such person as it may appoint for that purpose. Where there are one or more viaducts or bridges connecting two or more counties, the board of chosen freeholders of those counties or any joint committee having charge thereof, shall make rules and regulations for the protection and use thereof, and may place them in the special care or charge of such person or persons as they may appoint for that purpose. The person so appointed shall have the same powers as policemen in cities of the first class in respect to such viaduct, bridge or roads or its approaches for the enforcement of all laws, rules and regulations.
N.J.S. § 27:19-13