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

    <schemaVersion>X0306</schemaVersion>

    <documentType>5</documentType>

    <periodOfReport>2013-12-31</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <form3HoldingsReported>0</form3HoldingsReported>

    <form4TransactionsReported>0</form4TransactionsReported>

    <issuer>
        <issuerCik>0000002230</issuerCik>
        <issuerName>ADAMS EXPRESS CO</issuerName>
        <issuerTradingSymbol>ADX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001353074</rptOwnerCik>
            <rptOwnerName>Prue Nancy J F</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>THE ADAMS EXPRESS COMPANY</rptOwnerStreet1>
            <rptOwnerStreet2>7 SAINT PAUL STREET, SUITE 1140</rptOwnerStreet2>
            <rptOwnerCity>BALTIMORE</rptOwnerCity>
            <rptOwnerState>MD</rptOwnerState>
            <rptOwnerZipCode>21202</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>E.V.P.</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2013-12-31</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>78.97</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10949.28</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2013-12-31</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1807.58</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>15098.21</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Issuer's and Petroleum &amp; Resources Corp. Thrift Plan Trusts</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">These shares were acquired in exempt transactions as a result of dividend reinvestment.  The Issuer's stock traded in a range of $10.72 - $13.32 during 2013.</footnote>
        <footnote id="F2">Of these shares, 702.29 shares are held by the Issuer's Thrift Plan Trust and 1,105.29 shares are held by the Petroleum &amp; Resources Corp.'s Thrift Plan Trust and represent the undersigned's proportionate beneficial interest in the shares that were acquired by the Trust in 2013 in exempt transactions as a result of periodic contributions made during 2013 and shares acquired by the Trustee through dividend reinvestment in 2013.  The Issuer's stock traded in a range of $10.72 - $13.32 during 2013.</footnote>
        <footnote id="F3">The number of shares reported as held by the Issuer and by Petroleum &amp; Resources Corp.'s Thrift Plan Trust represents the undersigned's proportionate beneficial interest in such stock held in the Trust.  Such number is based on information as of December 31, 2013.  This number includes the shares acquired in exempt transactions through preriodic contributions made duirng 2013, shares acquired by the Trustee through dividend reinvestment, and changes in the number of shares previously reported due to fluctuations in the market price and interests in the Trust during 2013.  The Issuer's stock traded in a range of $10.72 - $13.32 during 2013.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Gail L. Valenti as Attorney-in-Fact for Nancy J. F. Prue</signatureName>
        <signatureDate>2014-02-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
