N.J. Stat. § 27:16-39
A county maintaining a road material yard for the storing, handling and distribution of road materials, may sell any surplus materials in its possession to the state highway commissioner, to municipalities within the county, or to contractors performing work for the state highway commissioner, counties, or municipalities within the county.
The sale shall be on the basis of cost, and the price therefor, quantity sold, and a statement that the materials were not needed by the county at the time of sale, certified by the supervisor of roads of the county, shall be posted immediately after a contract for sale shall be consummated, in the offices of the county treasurer and the clerk of the board of chosen freeholders for public inspection.
N.J.S. § 27:16-39