To require the Secretary of Transportation, in computing the estimated tax payments attributed to highway users for purposes of title 23, United States Code, to take into account the replacement of the reduced rates of tax on gasohol with an excise tax credit.

Requires the Secretary of Transportation to determine apportionments to States of Federal-aid highway funds for FY 2006 or any subsequent fiscal year in a particular manner if FY 2005 or any preceding fiscal year is taken into account in the computation. Directs the Secretary, in such an instance, to use the amount of estimated tax receipts that would have resulted if certain alcohol fuel mixture and biodiesel mixture excise tax credits under the American Jobs Creation Act of 2004 had taken effect at the beginning of the fiscal year taken into account.