<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-12-14</periodOfReport>

    <issuer>
        <issuerCik>0000099780</issuerCik>
        <issuerName>TRINITY INDUSTRIES INC</issuerName>
        <issuerTradingSymbol>NYSE/TRN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001078976</rptOwnerCik>
            <rptOwnerName>DUCHOSSOIS CRAIG J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>2525 STEMMONS FREEWAY</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>DALLAS</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>75207</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2004-12-14</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>4000000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>32.25</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3150000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>600000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>500000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>150</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Thrall Investment Company, L.L.C. (&quot;TIC&quot;) is the record owner of 3,150,000 shares; Thrall Car Management Company, Inc. (&quot;TCMC&quot;) is the record owner of 600,000 shares; and Thrall Investment Company II, L.L.C. (&quot;TIC II&quot;) is the record owner of 500,000 shares.  Mr. Duchossois is an operating board member and executive officer of TIC and TIC II, and a director and executive officer of TCMC, and has the ability to vote a majority of the voting interests in each of TIC, TIC II and TCMC.  Mr. Duchossois disclaims beneficial ownership of all shares held by TIC, TIC II and TCMC, except with respect to the pecuniary interest in such shares attributed to him by virtue of his direct or indirect equity interest in TIC, TIC II and TCMC.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>David L. Filkin, Attorney-in-Fact for  Craig J. Duchossois</signatureName>
        <signatureDate>2004-12-15</signatureDate>
    </ownerSignature>
</ownershipDocument>
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X0202
4
2004-12-14
0000099780
TRINITY INDUSTRIES INC
NYSE/TRN
0001078976
DUCHOSSOIS CRAIG J
2525 STEMMONS FREEWAY
DALLAS
TX
75207
1
0
0
0
Common Stock
2004-12-14
4
S
0
4000000
32.25
D
3150000
I
See Footnote
Common Stock
600000
I
See Footnote
Common Stock
500000
I
See Footnote
Common Stock
150
D
Thrall Investment Company, L.L.C. ("TIC") is the record owner of 3,150,000 shares; Thrall Car Management Company, Inc. ("TCMC") is the record owner of 600,000 shares; and Thrall Investment Company II, L.L.C. ("TIC II") is the record owner of 500,000 shares.  Mr. Duchossois is an operating board member and executive officer of TIC and TIC II, and a director and executive officer of TCMC, and has the ability to vote a majority of the voting interests in each of TIC, TIC II and TCMC.  Mr. Duchossois disclaims beneficial ownership of all shares held by TIC, TIC II and TCMC, except with respect to the pecuniary interest in such shares attributed to him by virtue of his direct or indirect equity interest in TIC, TIC II and TCMC.
David L. Filkin, Attorney-in-Fact for  Craig J. Duchossois
2004-12-15