N.J. Stat. § 27:22-12
Each board of chosen freeholders may appropriate funds to be used for the purpose of aiding municipalities in maintaining and repairing roads constructed or improved under the provisions of chapter 15 of this title (s. 27:15-1 et seq.). The amount of such appropriation shall not exceed the amount appropriated and paid for the maintenance of any such road by the municipality in which the road is located, nor shall the appropriation be made unless the municipality requests the board of chosen freeholders to use the funds allotted under sections 27:15-10 to 27:15-12 of this title for the maintenance of such roads and the board of chosen freeholders retains the funds allotted by the state highway commissioner to the municipality and uses them for that purpose.
N.J.S. § 27:22-12