N.J. Stat. § 48:12-58.1
Whenever a railroad company has discontinued or discontinues all traffic on any line or part thereof, and has abandoned or abandons the use of such line and the grade crossings thereon, said company shall notify the Board of Public Utility Commissioners and the Director of the Division of Motor Vehicles of its action. The Board of Public Utility Commissioners shall order the removal of the warning sign erected by the railroad in accordance with R.S. 48:12-58 and the installation in its place of a sign of such standard and design as shall be approved by the board, with the inscription "Abandoned Grade Crossing." When the railroad track has been removed or paved over at an abandoned grade crossing, no sign shall be required.
N.J.S. § 48:12-58.1