N.J. Stat. Ann. § 18A:39-2.1

Any board of education of a school district providing transportation for any child pursuant to N.J.S. 18A:46-23 to and from any other school district, may solicit any bid therefor, on a per pupil, per vehicle or per mileage basis, whichever is least costly to the school district of the board. The board may award any contract therefor pursuant to the provisions of chapter 39 of Title 18A of the New Jersey Statutes. Any adjustment in price authorized under the contract may be made on a per pupil, per vehicle or per mileage basis, whichever is least costly to the school district.