EXHIBIT 10.1

                               AMENDMENT NO. 3 TO
                SUPPLEMENTAL PROFIT SHARING PLAN FOR EMPLOYEES OF
               TRINITY INDUSTRIES, INC. AND CERTAIN AFFILIATES AS
                       RESTATED EFFECTIVE JANUARY 1, 2000

      WHEREAS, TRINITY INDUSTRIES, INC., a Delaware corporation (the "Company"),
has heretofore adopted the SUPPLEMENTAL PROFIT SHARING PLAN FOR EMPLOYEES OF
TRINITY INDUSTRIES, INC. AND CERTAIN AFFILIATES AS RESTATED EFFECTIVE JANUARY 1,
2000 ("the Plan") for the benefit of certain executive and managerial employees;
and

      WHEREAS, pursuant to those provisions of the Plan permitting the Company
to amend the Plan from time to time, the Company desires to amend the Plan in
certain respects as hereinafter provided;

      NOW THEREFORE, the Plan is hereby amended as follows, effective as of
January 1, 2004:

1.    Section 4.01(b) is hereby amended to be and read as follows:

            "(b)  Matching Employer Contribution. For Plan Years beginning prior
                  to January 1, 2004, for each Year, each Employer shall credit
                  a Matching Employer Contribution amount in the form of Stock
                  Units to each of its Employees for whom an amount was credited
                  pursuant to paragraph (a) of this Section 4.01; effective for
                  Plan Years beginning on and after January 1, 2004, such a
                  Matching Employer Contribution shall be credited in cash;
                  provided, however, that no such Matching Employer Contribution
                  shall be credited prior to the date on which such Employee
                  completes one (1) year of Service. Such Matching Employer
                  Contribution, when added to the Forfeitures which have become
                  available for application as of the end of the Year pursuant
                  to Section 4.03 hereof, shall be equal to a percentage of that
                  portion of the Participant's Compensation Reduction
                  Contribution for such Year pursuant to Section 4.02 hereof
                  which does not exceed six percent (6%) of his Base
                  Compensation plus Annual Incentive Compensation for such Year,
                  based on his years of Service as follows:





Years of Service          Applicable Percentage
- -----------------         ---------------------
                       
Less than 1                         0%
1 but less than 2                  25%
2 but less than 3                  30%
3 but less than 4                  35%
4 but less than 5                  40%
5 or more                          50%


                  For purposes of determining a Participant's Matching Employer
                  Contribution under this paragraph (b), if a Participant's
                  Employment Commencement Date is any date on or after January
                  1, 2001 and on or before March 31, 2001, and such Participant
                  is employed as of the last day of the Short Plan Year, he
                  shall be credited with a year of Service for such Short Plan
                  Year."

2.    Section 4.01(c) is hereby amended to be and read as follows:

            "(c)  Additional Matching Contribution. For Plan Years beginning
                  prior to January 1, 2004, for each Year, each Employer shall
                  credit an additional amount in the form of Stock Units to each
                  of its Employees for whom an amount was credited pursuant to
                  paragraph (a) of this Section 4.01, which when added to the
                  Forfeitures which have become available for application as of
                  the end of the Year pursuant to Section 4.03 hereof and which
                  have not been applied as provided in paragraph (b) of this
                  Section, shall be equal to seventeen and one-half percent
                  (17-1/2%) of that portion of the Participant's Compensation
                  Reduction Contribution for such Year pursuant to Section 4.02
                  hereof which is invested or deemed invested in Stock Units
                  pursuant to Section 5.02(a) hereof up to twenty-five percent
                  (25%) of the sum of his Base Compensation and Annual Incentive
                  Compensation for such Year. Effective for Plan Years beginning
                  on and after January 1, 2004, this paragraph (c) shall have no
                  further force or effect."

In accordance with the last sentence in the revised section 4.01(c) above,
references in the Plan to Additional Matching Contributions and Additional
Matching Contribution Accounts are applicable to such contributions and accounts
prior to January 1, 2004.

3.    Section 4.01(e) is hereby amended to be and read as follows:

            "(e)  Discretionary Contributions. For Plan Years beginning prior to
                  January 1, 2004, in addition to the contributions described
                  above, for each Year an Employer may, but shall not be
                  required to, credit the Discretionary

                                        2



                  Contribution Account of any one or more Participants in its
                  employ during such Year with such amounts in the form of Stock
                  Units or otherwise as the Employer may determine in its sole
                  discretion. Effective for Plan Years beginning on and after
                  January 1, 2004, if such amounts are credited, they shall be
                  credited in cash."

4.    Section 5.02 is hereby amended to be and read as follows:

      "5.02 Investment of Accounts

            (a)   Participant Election. The Committee shall credit each
                  Participant's Accounts with earnings or losses according to
                  the hypothetical investment selections made by the Participant
                  pursuant to his participation agreement executed pursuant to
                  Section 3.03 hereof. In accordance with certain limitations on
                  investment designations in Section 5.02(b), the Committee
                  shall adopt rules concerning the manner in which a Participant
                  may elect to change his hypothetical investment selections,
                  provided that a Participant shall be permitted to do so no
                  less frequently than as of the first day of each month.

                  For Plan Years beginning prior to January 1, 2004, the
                  earnings or losses attributable to a Participant's Accounts
                  shall be determined as if the amounts credited to such
                  Accounts were actually invested in Stock Units, to the extent
                  required or elected hereunder, and, to the extent not so
                  required or elected, in the hypothetical investments selected
                  under the Participant's participation agreement. In the case
                  of a Participant receiving installment payments under Article
                  VI hereof, the Participant's Accounts will continue to receive
                  allocations of earnings or losses in accordance with this
                  subsection until his Accounts are paid in full. If a
                  Participant's participation agreement fails to designate one
                  or more hypothetical investment selections, the Participant's
                  Account will be deemed invested in Stock Units, to the extent
                  required hereunder, and, to the extent not so required, in the
                  investment option designated as having the least investment
                  risk.

                  Effective for Plan Years beginning on and after January 1,
                  2004, the earnings or losses attributable to a Participant's
                  Accounts shall be determined as if the amounts credited to
                  such Accounts were actually invested in Stock Units, to the
                  extent elected hereunder, and, to the extent not so elected or
                  to the extent prohibited hereunder, in the hypothetical
                  investments selected under the Participant's participation
                  agreement. In the case of a Participant receiving installment
                  payments under Article VI hereof, the Participant's Accounts
                  will continue to receive allocations of earnings or losses in
                  accordance with this subsection until his Accounts are paid in
                  full. If a Participant's participation agreement fails to
                  designate one or more hypothetical investment selections, the
                  Participant's Account will be deemed invested in the
                  investment option designated as having the least investment
                  risk.

                                        3



            (b)   Investment Options. The Committee shall have sole and absolute
                  discretion with respect to the number and types of investment
                  options made available for selection by Participants pursuant
                  to this Section, the timing of Participant elections and the
                  method by which adjustments are made. The Committee may in its
                  sole discretion refuse to recognize Participant elections that
                  it determines may cause the Participant's Accounts to become
                  subject to the short-swing profit provisions of Section 16b of
                  the Securities Exchange Act of 1934 and establish special
                  election procedures for Participants subject to Section 16 of
                  such Act.

                  For Plan Years beginning prior to January 1, 2004, the
                  Committee shall permit Participants to designate that their
                  investments be treated as invested in (i) Stock Units or (ii)
                  one or more investment indices; provided that amounts credited
                  on or after the Effective Date to a Participant's Matching
                  Contribution Account or Additional Matching Contribution
                  Account shall at all times be invested in Stock Units;
                  provided further that Compensation Reduction Contributions
                  made on or after the Effective Date of Award Compensation
                  shall at all times be invested in Stock Units.

                  Effective for Plan Years beginning on and after January 1,
                  2004, amounts credited to a Participant's Matching
                  Contribution Account and Discretionary Contribution Account
                  shall at no time be treated as invested in Stock Units. For
                  Plan Years beginning on and after January 1, 2004,
                  Compensation Reduction Contributions may, at the Participant's
                  election, be treated as invested in Stock Units, provided
                  however, that following deemed investment in any media, such
                  Contributions may not be treated as transferred into or out of
                  deemed investments in Stock Units. For Plan Years beginning on
                  and after January 1, 2004, a Participant may not designate
                  that amounts credited to his Matching Contribution Account,
                  Additional Matching Contribution Account, Discretionary
                  Contribution Account, or Compensation Reduction Contribution
                  Account and deemed invested in any media be treated as
                  transferred into or out of deemed investments in Stock Units.

                  The designation of investment options by the Committee shall
                  be for the sole purpose of adjusting Accounts pursuant to this
                  Section, and except to the extent that deemed investment in
                  Stock Units was required hereunder for Plan Years beginning
                  prior to January 1, 2004, the provisions of this Article V
                  shall not obligate the Company or any of the Employers to
                  invest or set aside any assets for the payment of benefits
                  hereunder; provided, however, that the Company or an Employer
                  may invest a portion of its general assets in investments,
                  including investments which are the same as or similar to the
                  investment indices designated by the Committee and selected by
                  Participants, but any such investments shall remain part of
                  the general assets of the Company or such Employer and shall
                  not be deemed or construed to grant a property interest of any
                  kind to any Participant, designated Beneficiary or estate. The
                  Committee shall

                                        4



                  notify the Participants of the investment indices available
                  and the procedures for making and changing elections.

            (c)   Non-Binding Status of Elections. A Participant's hypothetical
                  investment selections pursuant to the immediately preceding
                  paragraph shall be made solely for purposes of crediting
                  earnings and/or losses to his Accounts under Section 5.03 of
                  this Plan. The Committee shall not, in any way, be bound to
                  actually invest any amounts set aside pursuant to Article VII
                  below to satisfy its obligations under this Plan in accordance
                  with such selections."

5.    Section 5.03(c) is hereby amended to be and read as follows:

            "(c)  Matching Contributions. For Plan Years beginning prior to
                  January 1, 2004, any Stock Units credited to a Participant by
                  an Employer pursuant to Section 4.01(b) or (c) during a Year
                  shall be allocated, as the case may be, to the Participant's
                  Matching Contribution Account or the Participant's Additional
                  Matching Contribution Account at such time as may be
                  determined by the Employer in its absolute discretion, but no
                  earlier than the last day of such Year.

                  Effective for Plan Years beginning on and after January 1,
                  2004, any amounts credited to a Participant by an Employer
                  pursuant to Section 4.01(b) during a Year shall be allocated
                  to the Participant's Matching Contribution Account at such
                  time as may be determined by the Employer in its absolute
                  discretion, but no earlier than the last day of such Year."

6.    Section 5.04(a) is hereby amended to be and read as follows:

            "(a)  General. For purposes of calculating the number of Stock Units
                  credited or deemed credited to a Participant's Accounts
                  pursuant to Section 5.03(b) and, for Plan Years beginning
                  prior to January 1, 2004, Section 5.03(d), the price of a
                  Stock Unit shall be equal to one hundred percent (100%) of the
                  closing price on the New York Stock Exchange of a share of the
                  Company's common stock on the date on which the Stock Units
                  are credited or deemed credited to the Participant's Accounts
                  (or if no shares of the Company's common stock are traded on
                  such date, on the immediately preceding trading date). For
                  Plan Years beginning prior to January 1, 2004, for purposes of
                  calculating the number of Stock Units credited to a
                  Participant's Accounts as an Employer Matching Contribution or
                  Additional Matching Contribution, the price of a Stock Unit
                  shall be equal to one hundred percent (100%) of the average
                  daily closing price on the New York Stock Exchange of a Share
                  of the Company's common stock for the Year with respect to
                  which the Stock Units are credited to the Participant's
                  Accounts, provided that for Stock Units credited with respect
                  to the Year ending March 31, 2000, such average daily closing
                  price shall be calculated

                                       5



                  for the period beginning on January 1, 2000 and ending on such
                  March 31, 2000."

7.    Section 5.04 (c) is hereby amended to be and read as follows:

            "(c)  Dividends. To the extent that a dividend is paid on the
                  Company's common stock, the Committee shall credit to the
                  Accounts of each Participant whose Accounts are invested or
                  deemed invested in Stock Units an amount equal to the value of
                  such dividends. Effective for Plan Years beginning prior to
                  January 1, 2004, such amounts shall be credited to the
                  Participant's Accounts in the form of additional Stock Units
                  at a price equal to one hundred percent (100%) of the closing
                  price on the New York Stock Exchange of a share of the
                  Company's common stock on the date on which such dividend is
                  paid (or if no shares of the Company's common stock are traded
                  on such date, on the immediately preceding trading date).
                  Effective for Plan Years beginning on and after January 1,
                  2004, such amounts shall be credited to the Participant's
                  Accounts in cash."

8.    Section 6.08 is hereby amended to be and read as follows:

      "6.08 Designated Distributions

            Prior to the beginning of a calendar year, a Participant may elect
            that all or any portion of the amount of any Compensation Reduction
            Contribution to be credited to the Participant's Compensation
            Reduction Contribution Account during such calendar year, be
            distributed to or on behalf of the Participant in the form of a lump
            sum in a subsequent calendar year designated by the Participant,
            which subsequent calendar year shall not be earlier than the third
            calendar year following the calendar year for which the election is
            made. Such an election shall be irrevocable. The distribution shall
            be made no later than December 31 of the designated year. In the
            event of the Participant's termination of employment for any reason
            prior to the designated year, the election shall be void and of no
            effect."

                                       6



      IN WITNESS WHEREOF, the Company has caused this instrument to be executed
in its name and on behalf of this ____day of _______________, 2004, effective as
of January 1, 2004.

                                         TRINITY INDUSTRIES, INC.

                                         By: ___________________________________

                                         Title: ________________________________

ATTEST:

_________________________

STATE OF TEXAS           Section
                         Section
COUNTY OF DALLAS         Section

      This instrument was acknowledged before me on the ___________ day of
______________________________ , 2004, by ______________________________________
of TRINITY INDUSTRIES, INC., a Delaware corporation, on behalf of said
corporation.

                                ________________________________________________
                                Notary Public in and for the
                                State of Texas

My Commission Expires:

_______________________________

                                       7