N.J. Stat. Ann. § 40:62-44

Any municipality engaging in the business of transportation may extend any system of transportation. No extension of any route or routes of such system exceeding one-fourth in length of the one authorized by any referendum shall be made, except by ordinance approved by the legal voters thereof, voting at a referendum election called and held in the manner provided in sections 40:62-36 to 40:62-39 of this title.