The FAST Act underlines the possible nature of the obligation presented by a framework credit agreement and specifies that it depends on the availability of future funds and compliance with all the conditions for granting credit aid under the TIFIA programme. In addition, the FAST Act specifies that the common security promised to support the framework credit agreement must receive an investment level rating at the time of the obligation of TIFIA credit aid. [23 U.S.C. 601(a)(10) and 602(b)(2)] TIFIA supports qualified projects of regional and national importance. The FAST Act defines a ”rural projects fund” as a fund created by a public infrastructure bank, capitalized and operated by a TIFIA loan to lend to rural infrastructure projects. [23 U.S.C. . .