§ 124. Advances to States
If the Secretary shall determine that it is necessary for the expeditious completion of projects on any of the Federal-aid systems, including the Interstate System, he may advance to any State out of any existing appropriations the Federal share of the cost of construction thereof to enable the State transportation department to make prompt payments for acquisition of rights-of-way, and for the construction as it progresses. The sums so advanced shall be deposited in a special revolving trust fund, by the State official authorized under the laws of the State to receive Federal-aid highway funds, to be disbursed solely upon vouchers approved by the State transportation department for rights-of-way which have been or are being acquired, and for construction which has been actually performed and approved by the Secretary pursuant to this chapter. Upon determination by the Secretary that any part of the funds advanced to any State under the provisions of this section are no longer required, the amount of the advance, which is determined to be in excess of current requirements of the State, shall be repaid upon his demand, and such repayments shall be returned to the credit of the appropriation from which the funds were advanced. Any sum advanced and not repaid on demand shall be deducted from sums due the State for the Federal pro rata share of the cost of construction of Federal-aid projects.