<?xml version="1.0"?>
<ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType><periodOfReport>2003-10-02</periodOfReport>
    <issuer>
        <issuerCik>0000099780</issuerCik>
        <issuerName>TRINITY INDUSTRIES INC</issuerName>
        <issuerTradingSymbol>NYSE/TRN</issuerTradingSymbol></issuer><reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001185206</rptOwnerCik>
            <rptOwnerName>HAY JESS T</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><nonDerivativeHolding><securityTitle><value>Common Stock</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>3000</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></nonDerivativeHolding><nonDerivativeHolding><securityTitle><value>Common Stock</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>384</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>by Spouse as custodian for child</value><footnoteId id="F2"/></natureOfOwnership></ownershipNature></nonDerivativeHolding><nonDerivativeTransaction><securityTitle><value>Common Stock</value></securityTitle><transactionDate><value>2003-10-02</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>W</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>1000</value></transactionShares><transactionPricePerShare><footnoteId id="F1"/></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>1000</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>by Spouse</value><footnoteId id="F2"/></natureOfOwnership></ownershipNature></nonDerivativeTransaction></nonDerivativeTable><footnotes><footnote id="F1">The reporting person's spouse acquired shares by inheritance.</footnote><footnote id="F2">The reporting person disclaims beneficial ownership of these securities, and this report shall not be deemed an admission that the reporting person is the beneficial owner of the securities for purposes of Section 16 or for any other purpose.</footnote></footnotes><remarks/><ownerSignature><signatureName>Michael G. Fortado  For:  Jess T. Hay</signatureName><signatureDate>2003-10-02</signatureDate></ownerSignature></ownershipDocument>
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X0201
4
2003-10-02
0000099780
TRINITY INDUSTRIES INC
NYSE/TRN
0001185206
HAY JESS T
2525 STEMMONS FREEWAY
DALLAS
TX
75207
1
0
0
0
Common Stock
3000
D
Common Stock
384
I
by Spouse as custodian for child
Common Stock
2003-10-02
4
W
0
1000
A
1000
I
by Spouse
The reporting person's spouse acquired shares by inheritance.
The reporting person disclaims beneficial ownership of these securities, and this report shall not be deemed an admission that the reporting person is the beneficial owner of the securities for purposes of Section 16 or for any other purpose.
Michael G. Fortado  For:  Jess T. Hay
2003-10-02