An amendment to provide that sums apportioned for Interstate System in any State shall remain available for expenditure in that State for the Interstate System until the end of the fiscal year for which authorized. Sums not obligated within that time period must be made available by the Secretary to any other State applying for such funds for the Interstate System, if the Secretary determines that the State has obligated all of its apportionments other than an amount which, by itself, is insufficient to pay the Federal share of the cost of a project on the Interstate System which has been submitted by such State to the Secretary for approval, and the applicant is willing and able to (A) obligate the funds within one year of the date the funds that are made available; (B) apply them on a read-to-commence project; (C) in the case of construction work, begin work within ninety days of obligation. Those shall be available until expended.