The following applies to Federal assistance programs and projects funded out of the Federal Highway Trust Fund, notwithstanding any other provision of this part:
(a) A State must request funds at least weekly for current project costs, or Federal interest liability will not accrue prior to the day a State submits a request for funds.
(b) If a State pays out its own funds in the absence of a project agreement or in excess of the Federal obligation in a project agreement, the Federal Program Agency will not incur an interest liability.