A bill to amend section 103 of title 23 of the United States Code relating to additional mileage for the Interstate System and the Highway Revenue Act of 1956 by extending the duration of the Highway Trust Fund for the construction of certain highways, and for other purposes.

Extends the date for completion of the Interstate Highway System provided for under the Highway Revenue Act of 1956 from June 30, 1976 to June 30, 1981.

Provides that, upon approval by the Congress, the Secretary of Transportation shall use the Federal share of his approved estimate in making apportionments for the Interstate Highway System for the fiscal years ending June 30, 1976 and June 30, 1977. Directs the Secretary of Transportation to make a revised estimate of the cost of completing the Interstate System after taking into account all previous apportionments made under the Highway Revenue Act and to transmit the same to the Senate and House of Representatives within ten days subsequent to January 2, 1976 (for the purpose of apportioning Federal funds for the fiscal years ending June 30, 1978 and June 30, 1979), and within ten days subsequent to January 2, 1978 (for purpose of apportioning Federal funds for the fiscal years ending June 30, 1980, and June 30, 1981).

Authorizes additional mileage of five thousand eight hundred miles under the Highway Revenue Act for an interstate route from Kansas City, Missouri, to connect with Interstate 95 in Georgia and such additional mileage as may be required elsewhere in the United States.

Extends the provisions of the Highway Trust Fund for five years in order to provide financing for the Interstate Highway system extension stipulated in the Act. (Amends 23 U.S.C. 101(b); Amends 23 U.S.C. 104(b) 5; Amends 23 U.S.C 103(e)(i); Adds 23 U.S.C. 103(e)(4); Amends 23 U.S.C. 120(c)(e)(F)nt)