N.J. Stat. Ann. § 27:8-4

The commissioner shall not incur any liability or otherwise commit the state to an expenditure in excess of the unrequisitioned balances of any funds at his disposal, available for road work, but after delivery of the contract from any governing body under this chapter the amount to be paid by that governing body shall be considered as an addition to such unrequisitioned balances in ascertaining the available means to secure aid from said government.