To authorize appropriations for construction of Federal-aid highways in accordance with title 23, United States Code, and for other purposes.

Directs the Secretary of Transportation to apportion for all States for FY 1993 sums authorized to be appropriated for such year by the Federal-Aid Highway Act of 1956 for expenditure on the Dwight D. Eisenhower National System of Interstate and Defense Highways, using specified apportionment factors.

Extends the apportionment of funds for the Federal highway program through 1993.

Authorizes appropriations of one-sixth of the funding under the Surface Transportation and Uniform Relocation Assistance Act of 1987 (STURAA) for FY 1991 for use in FY 1992 and 1993.

Makes provisions of STURAA dealing with disadvantaged business enterprise requirements applicable to amounts authorized to be appropriated under this Act.

Extends through 1992: (1) the Federal-Aid Primary apportionment formula; and (2) the off-system bridge program.

Authorizes appropriations for FY 1992 for the interstate highway substitute program.

Provides for funding (at a reduced level) for the interstate and bridge discretionary programs.

Amends the Department of Transportation and Related Agencies Appropriations Act, 1988 to extend the 65 mile per hour speed limit demonstration program.