a. The authority, in the exercise of its power to make and enter into contracts and agreements necessary or incidental to the performance of its duties and the execution of its powers, shall adopt standing operating rules and procedures providing that, except as hereinafter provided, no contract on behalf of the authority shall be entered into for the doing of any work, or for the hiring of equipment or vehicles, when the sum to be expended exceeds the sum of $25,000 or, after the effective date of P.L. 1999, c. 440, the amount determined pursuant to subsection b. of this section, unless the authority shall first publicly advertise for bids therefor, and shall award the contract to the lowest responsible bidder; provided, however, that such advertising shall not be required when the contract to be entered into is one for the furnishing or performing of services of a professional nature, or when the purchase is to be made through or by the Director of the Division of Purchase and Property pursuant to section 1 of P.L. 1959, c.40 (C.52:27B-56.1), or through a contract made by any of the following: the New Jersey Sports and Exposition Authority established under section 4 of P.L. 1971, c.137 (C.5:10-4); the Hackensack Meadowlands Development Commission established under section 5 of P.L. 1968, c.404 (C.13:17-5); the New Jersey Highway Authority established under section 4 of P.L. 1952, c.16 (C.27:12B-4); the New Jersey Turnpike Authority established under section 3 of P.L. 1948, c.454 (C.27:23-3); the New Jersey Water Supply Authority established under section 4 of P.L. 1981, c.293 (C.58:1B-4); the South Jersey Transportation Authority established under section 4 of P.L. 1991, c.252 (C.27:25A-4); the Port Authority of New York and New Jersey established under R.S. 32:1-4; and the Delaware River Port Authority established under R.S. 32:3-2. Waiver of bid advertising and of actual bidding shall be made by resolution of the authority for those goods, services, and contracts described in sections 4 and 5 of P.L. 1954, c.48 (C.52:34-9 and 52:34-10). This subsection shall not prevent the authority from having any work done by its own employees, nor shall it apply when the safety or protection of its or other public property requires. In the case of exigency or emergency, the authority shall, by resolution passed by the affirmative vote of a majority of its members, declare the exigency or emergency to exist, and set forth in the resolution the nature thereof and the approximate amount to be so expended.