To codify without substantive change recent laws related to transportation and to improve the United States Code.

(Sec. 1) Codifies specified provisions of Federal transportation law.

(Sec. 6) Amends Federal transportation law to require the Secretary of Transportation (Secretary) to prescribe regulations requiring a preaward and postdelivery review of grants to buy rolling stock to ensure compliance with Government motor vehicle safety requirements, Buy America requirements, and certain bid specifications requirements.

Includes the Northern Mariana Islands within the meaning of a "State" with respect to passenger motor vehicle country of origin labeling requirements.

Revises provisions requiring the Administrator of the Environmental Protection Agency to make separate calculations of the average fuel economy for passenger automobiles manufactured both domestically and in foreign countries (especially in Canada and Mexico) and sold in the United States.

Revices fuel economy labeling requirements to require automobile dealers to display such labels on the automobile.

Defines "retrofit device" to mean any component, equipment, or other device that: (1) is designed to be installed in or on an automobile as an addition to, as a replacement for, or through alteration of, such items; and (2) any manufacturer, dealer, or distributor of the device represents will provide higher fuel economy than would have resulted with the automobile as originally equipped. Includes fuel additives for use in an automobile.

Requires the Federal Trade Commission (FTC) to establish a program for systematically examining fuel economy representations made with respect to retrofit devices. Directs the Administrator of the FTC to prescribe regulation establishing tests and procedures for evaluating such devices.

Authorizes the Secretary to develop and construct a civil supersonic aircraft.

Requires an air carrier, in order to hold a certificate of public convenience and necessity authorizing it to provide air transportation, to continue to be fit, willing, and able to provide such transportation and to comply with certain other requirements. Sets forth certain notice requirements which air carriers holding certificates to provide foreign air transportation must meet in order to end or suspend such transportation. Authorizes the Secretary to suspend foreign air transportation temporarily when it is in the public interest.

Extends from FY 1993 through FY 1996 the Secretary's authority to make airport improvement grants. Excepts from the termination of such authority on September 30, 1996, in addition to obligations of amounts remaining available after such date, any obligations of amounts recovered by the Government from grants made if the amounts are obligated for increases in the maximum amount of Government obligations for any other airport planning and development grants. Revises criteria for determining whether project costs are allowable. Increases the minimum amount that may be apportioned to sponsors of primary airports in a fiscal year. Declares that, if a law limits the amount subject to apportionment for airport planning and development projects in any fiscal year to less than $1.9 billion, the total apportionment for primary and cargo service airports shall not exceed 44 percent of such amount.

Requires a specified amount of funds for airport planning and development to be credited to the Secretary's discretionary fund.

Requires not less than five percent (currently, ten percent) of funds for airport planning and development to be distributed to reliever airports. Requires not less than 1.5 percent (currently, 2.5 percent) of such funds to be distributed to: (1) nonprimary commercial service airports; and (2) certain noncommercial service public airports. Requires not less than .75 percent (currently, .5 percent) of such funds to be distributed for integrated airport system planning grants.

Makes available not more than $200,000 of funds from the discretionary fund for terminal development costs at reliever airports, including costs allowable for commercial service airports that each year do not have more than .05 percent of the total boardings in the United States. Makes amounts available from such fund and the small airport fund for use by primary airports that each year do not have more than .05 percent of the total boardings in the United States.

Requires the Secretary to establish procedures to notify the Administration of any pipeline accident in which an excavator that has caused damage to a pipeline may have violated an Administration regulation.

(Sec. 8) Repeals specified laws.