N.J. Stat. Ann. § 40:67-16

The governing body may establish safety zones, erect, construct and maintain platforms, commonly called "safety aisles" ; standards commonly called "silent policemen" , beacon lights, guide posts and other structures which it may deem necessary for the safety and convenience of persons and vehicles using the streets of such municipality, but no such erections or constructions shall be made, operated or maintained on any state highway without permission of the state highway commission; nor shall any such erections or constructions be made, operated or maintained on any county road or county boulevard without permission of the board or body having control of or jurisdiction over such county road or boulevard.