New Jersey Statutes Title 39. Motor Vehicles and Traffic Regulation 39 § 3-54.21

a. Any employee of the United States Postal Service who, as part of his assigned duties as a rural route letter carrier, is required to use a motor vehicle owned or leased by him or a member of his family in the performance of his duties may display on that motor vehicle an amber warning light.

The amber warning lights may be operated only while the motor vehicle is being used by the United States Postal Service employee in the performance of his duties as a rural letter carrier.

The amber warning light authorized under the provisions of this act shall be temporarily attached, removable lights of the flashing or revolving type, not more than 7 1/2 inches in diameter, not more than 51 candlepower, and shall be controlled by a switch installed inside the vehicle.

While in operation, the amber warning light shall be conspicuously displayed on the roof of the motor vehicle.

Nothing herein shall be construed to grant any person displaying and operating an amber warning light pursuant to the provisions of this act any privileges or exemptions denied to the drivers of other motor vehicles and all such persons shall drive with due regard for the safety of all persons and shall obey the traffic laws of this State.

b. The Director of the Division of Motor Vehicles, in accordance with the provisions of the “Administrative Procedure Act,” P.L.1968, c. 410 (C.52:14B-1 et seq.), shall promulgate rules and regulations to effectuate the purposes of this act.