SECTION 1. CLEAN-FUEL VEHICLES USED BY ENTERPRISE ZONE BUSINESSES.

    (a) In General.--Part III of subchapter U of chapter 1 of the 
Internal Revenue Code of 1986 (relating to additional incentives for 
empowerment zones) is amended by redesignating subpart C as subpart D, 
by redesignating sections 1397B and 1397C as sections 1397C and 1397D, 
respectively, and by inserting after subpart B the following new 
subpart:

            ``Subpart C--Incentives For Clean-Fuel Vehicles

                              ``Sec. 1397B. Incentives for clean-fuel 
                                        vehicles.

``SEC. 1397B. INCENTIVES FOR CLEAN-FUEL VEHICLES.

    ``(a) Empowerment Zone Clean Fuels Credit.--For purposes of section 
38, the amount of the empowerment zone clean fuels credit determined 
under this section for the taxable year is the sum of--
            ``(1) the empowerment zone clean-fuel property credit, plus
            ``(2) the empowerment zone clean-burning fuel use credit.
    ``(b) Empowerment Zone Clean-Fuel Property Credit.--
            ``(1) In general.--The empowerment zone clean-fuel property 
        credit is the cost of--
                    ``(A) qualified clean-fuel vehicle property, and
                    ``(B) qualified clean-fuel vehicle refueling 
                property,
        paid or incurred for the taxable year by an eligible enterprise 
        zone business.
            ``(2) Limitations.--
                    ``(A) Qualified clean-fuel vehicle property.--The 
                cost which may be taken into account under paragraph 
                (1)(A) with respect to any motor vehicle shall not 
                exceed--
                            ``(i) $2,000 in the case of a motor vehicle 
                        not described in clause (ii) or (iii),
                            ``(ii) $5,000 in the case of any truck or 
                        van with a gross vehicle weight rating greater 
                        than 10,000 pounds but not greater than 26,000 
                        pounds, or
                            ``(iii) $50,000 in the case of--
                                    ``(I) a truck or van with a gross 
                                vehicle weight rating greater than 
                                26,000 pounds, or
                                    ``(II) any bus which has a seating 
                                capacity of at least 20 adults (not 
                                including the driver).
                    ``(B) Qualified clean-fuel vehicle refueling 
                property.--
                            ``(i) In general.--The aggregate cost which 
                        may be taken into account under paragraph 
                        (1)(B) with respect to qualified clean-fuel 
                        vehicle refueling property placed in service 
                        during the taxable year at a location shall not 
                        exceed the lesser of--
                                    ``(I) $100,000, or
                                    ``(II) the cost of such property 
                                reduced by the amount described in 
                                clause (ii).
                            ``(ii) Reduction for amounts previously 
                        taken into account.--For purposes of clause 
                        (i)(II), the amount described in this clause is 
                        the amount determined by adding--
                                    ``(I) the aggregate amount taken 
                                into account under paragraph (1)(B) for 
                                all preceding taxable years, plus
                                    ``(II) the aggregate amount taken 
                                into account under section 
                                179A(a)(1)(B) by the taxpayer (or any 
                                related person or predecessor) with 
                                respect to property placed in service 
                                at such location for all preceding 
                                taxable years.
                            ``(iii) Special rules.--For purposes of 
                        this subparagraph, the provisions of 
                        subparagraphs (B) and (C) of section 179A(b)(2) 
                        shall apply.
    ``(c) Empowerment Zone Clean-Burning Fuel Use Credit.--The 
empowerment zone clean-burning fuel use credit is the amount equal to 
50 cents for each gasoline gallon equivalent of clean-burning fuel used 
by an eligible enterprise zone business during the taxable year to 
propel qualified clean-fuel vehicle property.
    ``(d) Definitions.--For purposes of this section--
            ``(1) Eligible enterprise zone business.--The term 
        `eligible enterprise zone business' means--
                    ``(A) an enterprise zone business (as defined 
                section 1397C) located within an empowerment zone that 
                is within a nonattainment area (within the meaning of 
                section 171 of the Clean Air Act), and
                    ``(B) a trade or business located outside of an 
                empowerment zone, but only with respect to qualified 
                clean-fuel vehicle property used substantially within 
                an empowerment zone that is within a nonattainment area 
                (within the meaning of section 171 of the Clean Air 
                Act).
            ``(2) Clean-burning fuel.--The term `clean-burning fuel' 
        has the meaning given to such term by section 179A, except that 
        such term includes compressed natural gas.
            ``(3) Qualified clean-fuel vehicle property.--The term 
        `qualified clean-fuel vehicle property' has the meaning given 
        to such term by section 179A(c) without regard to paragraph (3) 
        thereof, except that such term does not include any motor 
        vehicle that is propelled by a fuel that is not a clean-burning 
        fuel.
            ``(4) Qualified clean-fuel vehicle refueling property.--The 
        term `qualified clean-fuel vehicle refueling property' has the 
        meaning given to such term by section 179A(d).
            ``(5) Gasoline gallon equivalent.--The term `gasoline 
        gallon equivalent' means, with respect to any clean burning 
        fuel, the amount (determined by the Secretary) of such fuel 
        having a Btu content of 114,000.
    ``(e) Denial of Double Benefit.--No credit shall be allowed under 
subsection (a) for any expense for which a deduction or credit is 
allowed under any other provision of this chapter.''.
    (b) Credit Made Part of General Business Credit.--Subsection (b) of 
section 38 of such Code is amended by striking ``plus'' at the end of 
paragraph (11), by striking the period at the end of paragraph (12) and 
inserting ``, plus'', and by adding at the end thereof the following 
new paragraph:
            ``(13) the empowerment zone clean fuels credit determined 
        under section 1397B.''.
    (c) Denial of Double Benefit.--Section 280C of such Code is amended 
by adding at the end thereof the following new subsection:
    ``(d) Empowerment Zone Clean Fuels Expenses.--No deduction shall be 
allowed for that portion of expenses for clean-burning fuel otherwise 
allowable as a deduction for the taxable year which is equal to the 
amount of the credit determined for such taxable year under section 
1397B.''.
    (d) Credit Allowed Against Regular and Minimum Tax.--
            (1) In general.--Subsection (c) of section 38 of such Code 
        (relating to limitation based on amount of tax) is amended by 
        redesignating paragraph (3) as paragraph (4) and by inserting 
        after paragraph (2) the following new paragraph:
            ``(3) Special rules for empowerment zone clean fuels 
        credit.--
                    ``(A) In general.--In the case of the empowerment 
                zone clean fuels credit--
                            ``(i) this section and section 39 shall be 
                        applied separately with respect to the credit, 
                        and
                            ``(ii) in applying paragraph (1) to the 
                        credit--
                                    ``(I) subparagraph (A) thereof 
                                shall not apply, and
                                    ``(II) the limitation under 
                                paragraph (1) (as modified by subclause 
                                (I)) shall be reduced by the credit 
                                allowed under subsection (a) for the 
                                taxable year (other than the 
                                empowerment zone clean fuels credit).
                    ``(B) Empowerment zone clean fuels credit.--For 
                purposes of this subsection, the term `empowerment zone 
                clean fuels credit' means the credit allowable under 
                subsection (a) by reason of section 1397B.''.
            (2) Conforming amendment.--Subclause (II) of section 
        38(c)(2)(A)(ii) of such Code is amended by inserting ``or the 
        empowerment zone clean fuels credit'' after ``employment 
        credit''.
    (e) Limitation on Carryback.--Subsection (d) of section 39 of such 
Code is amended by adding at the end thereof the following new 
paragraph:
            ``(9) No carryback of empowerment zone clean fuels credit 
        before effective date.--No portion of the unused business 
        credit for any taxable year which is attributable to the credit 
        determined under section 1397B may be carried back to any 
        taxable year ending before the date of the enactment of section 
        1397B.''.
    (f) Deduction for Certain Unused Business Credits.--Subsection (c) 
of section 196 of such Code is amended by striking ``and'' at the end 
of paragraph (6), by striking the period at the end of paragraph (7) 
and inserting ``, and'', and by adding after paragraph (7) the 
following new paragraph:
            ``(8) the empowerment zone clean fuels credit determined 
        under section 1397B.''.
    (g) Conforming Amendments.--
            (1) Paragraph (3) of section 1394(b) of such Code is 
        amended by striking ``section 1397B'' each place it appears and 
        inserting ``1397C''.
            (2) Paragraph (3) of section 1394(f) of such Code is 
        amended by striking ``sections 1397B and 1397C'' and inserting 
        ``sections 1397C and 1397D''.
            (3) Subsection (e) of section 1400 of such Code is amended 
        by striking ``section 1397B'' and inserting ``section 1397C''.
            (4) Subsection (c) of section 1400B of such Code is amended 
        by striking ``section 1397B'' both places it appears and 
        inserting ``section 1397C''.
    (h) Clerical Amendments.--
            (1) The table of subparts for part III of subchapter U of 
        chapter 1 of such Code is amended by striking the last item and 
        inserting the following:

                              ``Subpart C. Incentives for clean-fuel 
                                        vehicles.
                              ``Subpart D. General provisions.''.
            (2) The table of sections for subpart D, as amended by 
        paragraph (1) of this subsection, is amended to read as 
        follows:

                              ``Sec. 1397C. Enterprise zone business 
                                        defined.
                              ``Sec. 1397D. Qualified zone property 
                                        defined.''.
    (i) Effective Date.--The amendments made by this section shall 
apply to costs paid or incurred after December 31, 1997.
Amends the Internal Revenue Code to establish, for the use of clean-fuel vehicles by enterprise zone businesses, an empowerment zone clean fuels credit equal to the sum of the:  (1) empowerment zone clean-fuel property credit; and (2) empowerment zone clean-burning fuel use credit.
To amend the Internal Revenue Code of 1986 to provide additional incentives for the use of clean-fuel vehicles by enterprise zone businesses within empowerment zones.