<PAGE>

                                                                   EXHIBIT 10.13

                            THIRD AMENDMENT TO THIRD
                      AMENDED AND RESTATED CREDIT AGREEMENT

         THIS THIRD AMENDMENT TO THIRD AMENDED AND RESTATED CREDIT AGREEMENT
(this "Third Amendment"), dated as of May 30, 2003, by and among the lenders
listed on the signature pages hereof as Lenders (the "Lenders"), DYNAMEX INC., a
Delaware corporation (the "Borrower"), DYNAMEX OPERATIONS EAST, INC., a Delaware
corporation, DYNAMEX OPERATIONS WEST, INC., a Delaware corporation, ROAD RUNNER
TRANSPORTATION, INC., a Minnesota corporation, NEW YORK DOCUMENT EXCHANGE
CORPORATION, a New York corporation, DYNAMEX DEDICATED FLEET SERVICES, INC., a
Delaware corporation, DYNAMEX CANADA HOLDINGS, INC., a Delaware corporation,
DYNAMEX PROVINCIAL COURIERS, INC., a Delaware corporation, DYNAMEX CANADA
HOLDINGS NS CORP., a Nova Scotia (Canada) unlimited liability company, DYNAMEX
PROVINCIAL COURIERS NS CORP., a Nova Scotia (Canada) unlimited liability
company, DYNAMEX CANADA LIMITED PARTNERSHIP, a Nova Scotia (Canada) limited
partnership, DYNAMEX CANADA CORP., a Nova Scotia (Canada) unlimited liability
company, ALPINE ENTERPRISES LTD., a Manitoba (Canada) corporation, BANK OF
AMERICA, N.A., as administrative agent for itself and the other Lenders (in such
capacity, the "Administrative Agent"), and BANK ONE, NA, as syndication agent
under the Credit Agreement (in such capacity, the "Syndication Agent").

                                   BACKGROUND

         A.       The Borrower, the other Loan Parties (as defined in the Credit
Agreement defined below), the Lenders, the Syndication Agent, and the
Administrative Agent are parties to that certain Third Amended and Restated
Credit Agreement, dated as of November 9, 2001, as amended by that certain First
Amendment to Third Amended and Restated Credit Agreement, dated as of September
27, 2002, and that certain Second Amendment to Third Amended and Restated Credit
Agreement, dated as of October 4, 2002 (said Third Amended and Restated Credit
Agreement, the "Credit Agreement"; the terms defined in the Credit Agreement and
not otherwise defined herein shall be used herein as defined in the Credit
Agreement).

         B.       The Borrower has requested (a) certain amendments to the
Credit Agreement and (b) to remove Fleet National Bank ("Fleet") and Bank
Austria Creditanstalt Corporate Finance, Inc. ("Bank Austria") (collectively,
"Exiting Lenders") as lenders under the Credit Agreement.

         C.       The Borrower, the Lenders, the Syndication Agent and the
Administrative Agent hereby agree to amend the Credit Agreement, subject to the
terms and conditions set forth herein.

         NOW, THEREFORE, in consideration of the covenants, conditions and
agreements hereafter set forth, and for other good and valuable consideration,
the receipt and adequacy of which are all hereby acknowledged, the parties
hereto covenant and agree as follows:

                                       1

<PAGE>

         1.       AMENDMENTS.

         (a)      The definition of "Amortizing Loan Portion" set forth in
Section 1.1 of the Credit Agreement is hereby amended to read as follows:

                  "Amortizing Loan Portion" means that portion of the aggregate
         principal amount of the Loans outstanding as of the Third Amendment
         Effective Date in an amount equal to $13,000,000. As of the Third
         Amendment Effective Date, the Amortizing Loan Portion of each Lender is
         the amount set forth opposite the name of such Lender on the signature
         pages to the Third Amendment under the heading "Amortizing Loan
         Portion".

         (b)      The definition of "Applicable Margin" set forth in Section 1.1
Of the Credit Agreement is hereby amended to read as follows:

                  "Applicable Margin" means the following percentages per annum,
         based upon the ratio of Total Debt to EBITDA as set forth in the most
         recent Compliance Certificate received by the Administrative Agent
         pursuant to Section 8.1(c):

<TABLE>
<CAPTION>
----------------------------------------------------------------------------------------------------------
PRICING             RATIO OF TOTAL DEBT TO             COMMITMENT         EURODOLLAR LOANS       ABR
 LEVEL                     EBITDA                         FEE             LETTERS OF CREDIT     LOANS
----------------------------------------------------------------------------------------------------------
<S>         <C>                                        <C>                <C>                   <C>
   1        Less than 1.25 to 1.00                       0.250                  2.000             0.000
----------------------------------------------------------------------------------------------------------
   2        Greater than or equal to 1.25                0.375                  2.500             0.125
            to 1.00 but less than 1.75 to 1.00
----------------------------------------------------------------------------------------------------------
   3        Greater than or equal to 1.75 to 1.00        0.500                  3.500             0.500
----------------------------------------------------------------------------------------------------------
</TABLE>

                  Any increase or decrease in the Applicable Margin resulting
         from a change in the ratio of Total Debt to EBITDA shall become
         effective as of the first Business Day immediately following the end of
         the compliance period for which a Compliance Certificate is delivered
         pursuant to Section 8.1(c); provided, however, that if a Compliance
         Certificate is not delivered when due in accordance with such Section,
         then Pricing Level 3 shall apply as of the first Business Day after the
         date on which such Compliance Certificate was required to be have been
         delivered. The Applicable Margin from and after the Third Amendment
         Effective Date through the date on which another Pricing Level would
         otherwise be in effect based on the Compliance Certificate of the
         Borrower shall be Pricing Level 3.

         (c)      The definition of "Commitment" set forth in Section 1.1 of the
Credit Agreement is hereby amended to read as follows:

                  "Commitment" means, as to any Lender, the obligation of such
                  Lender to make Loans under the Revolving Loan Portion
         of the Loans and incur or participate in Letter of Credit Liabilities
         hereunder in an aggregate principal amount at any one time outstanding
         up to but not exceeding the amount set forth opposite the name of such
         Lender on the signature pages to the Third Amendment (or any further
         amendment to the Credit

                                       2

<PAGE>

         Agreement) under the heading "Commitment" or, if such Lender is a party
         to an Assignment and Acceptance, the amount of the "Commitment" set
         forth in the most recent Assignment and Acceptance of such Lender, as
         the same may be reduced or terminated pursuant to Section 2.12 or 11.2,
         and "Commitments" means such obligations of all Lenders. As of the
         Third Amendment Effective Date, the aggregate principal amount of the
         Commitments is $19,500,000.

         (d)      The defined term "Commitment Fee Rate" set forth in Section
1.1 of the Credit Agreement is hereby deleted.

         (e)      The defined term "Dividends" is hereby added to Section 1.1 of
the Credit Agreement in proper alphabetical order to read as follows:

                  "Dividends" means any dividend or other distribution (whether
         in cash, Property or obligations), direct or indirect, on account of
         (or the setting apart of money for a sinking or other analogous fund
         for) any shares of any class of Capital Stock of the Borrower or any of
         its Subsidiaries now or hereafter outstanding, except a dividend
         payable solely in shares of that class of stock to the holders of that
         class.

         (f)      The definition of "Eligible Receivables" set forth in Section
1.1 Of the Credit Agreement is hereby amended by amending clause (o) of such
definition to read as follows:

                  (o)      Such Receivable is not owed by an account debtor as
         to which more than twenty percent of the aggregate balances then
         outstanding on all Receivables owed by such account debtor thereon
         and/or its Affiliates to the Borrower or one of its Subsidiaries (as
         applicable) are more than 90 days past the original date of invoice;
         provided, that if a single invoice causes the outstanding Receivables
         from an account debtor that are over 90 days past due to be greater
         than twenty percent of the aggregate Receivables owed by such account
         debtor, but such Receivables from such invoice otherwise are "Eligible
         Receivables" but for this clause (o) or clause (c) of the definition,
         then only such Receivables from such invoice will be excluded in
         determining "Eligible Receivables";

         (g)      The definition of "Fixed Charge Coverage Ratio" set forth in
Section 1.1 Of the Credit Agreement is hereby amended to read as follows:

                  "Fixed Charge Coverage Ratio" means, for any period, the ratio
         of (a) the sum of the following (without duplication) for the Borrower
         and its Subsidiaries for such period determined on a consolidated basis
         in accordance with GAAP: (i) Net Income, plus (ii) Interest Expense,
         plus (iii) income and franchise taxes to the extent deducted in
         determining Net Income, plus (iv) depreciation and amortization expense
         and other non-cash items to the extent deducted in determining Net
         Income, minus (v) non-cash income to the extent included in determining
         Net Income, plus (vi) Lease Expense, minus (vii) Capital Expenditures,
         minus (viii) Dividends to (b) the Fixed Charges of the Borrower and its
         Subsidiaries for such period.

         (h)      The definition of "Interest Rate Protection Agreements" set
forth in Section 1.1 of the Credit Agreement is hereby amended to read as
follows:

                                       3

<PAGE>

                  "Interest Rate Protection Agreements" means, with respect to
         any Person, an interest rate swap, cap or collar agreement or similar
         arrangement between such Person and one or more Lenders that are
         parties to this Agreement (or Affiliates of such Lenders) providing for
         the transfer or mitigation of interest rate risks either generally or
         under specified contingencies.

         (i)      The definition of "Loan Documents" set forth in Section 1.1 of
the Credit Agreement is hereby amended to read as follows:

                  "Loan Documents" means this Agreement, the Notes, the Security
         Documents, the Indemnity, Subrogation and Contribution Agreement, the
         Administrative Agent's Letter, the Letters of Credit, the Letter of
         Credit Agreements, the Joinder Agreements, any Interest Rate Protection
         Agreement or Currency Hedge Agreement between the Borrower or any of
         its Subsidiaries and any Lender or any Affiliate of a Lender, and all
         other agreements, documents and/or instruments now or hereafter
         executed and/or delivered pursuant to or in connection with any of the
         foregoing, and any and all amendments, modifications, supplements,
         renewals, extensions, restatements or replacements thereof.

         (j)      The definition of "Maturity Date" set forth in Section 1.1 of
the Credit Agreement is hereby amended to read as follows:

                  "Maturity Date" means November 30, 2005.

         (k)      The definition of "Obligations" set forth in Section 1.1 of
the Credit Agreement is hereby amended to read as follows:

                  "Obligations" means any and all (a) indebtedness, liabilities
                  and obligations of the Borrower and the other Loan
         Parties, or any of them, to the Administrative Agent, the Issuing Bank
         and the Lenders, or any of them, evidenced by and/or arising pursuant
         to any of the Loan Documents (including, without limitation, this
         Agreement, the Notes and the Guaranties), now existing or hereafter
         arising, whether direct, indirect, related, unrelated, fixed,
         contingent, liquidated, unliquidated, joint, several or joint and
         several, including, without limitation, (i) the obligations of the
         Borrower and the Guarantors to repay the Loans and the Reimbursement
         Obligations, to pay interest on the Loans and the Reimbursement
         Obligations (including, without limitation, interest accruing after
         any, if any, bankruptcy, insolvency, reorganization or other similar
         filing) and to pay all fees, indemnities, costs and expenses (including
         attorneys' fees) provided for in the Loan Documents and (ii) the
         indebtedness constituting the Loans, the Reimbursement Obligations and
         such interest, fees, indemnities, costs and expenses, (b) indebtedness,
         liabilities and obligations of the Borrower or any of its Subsidiaries
         under any and all Interest Rate Protection Agreements and Currency
         Hedge Agreements that it may enter into with any Lender or any
         Affiliate of a Lender with the prior written consent of the
         Administrative Agent and the Required Lenders (whether or not such
         Lender remains as a Lender after the execution of any such Interest
         Rate Protection Agreement or Currency Hedge Agreement, unless the
         Administrative Agent and the Required Lenders otherwise provide in
         connection with or as a condition to their consent), and (c)
         indebtedness,

                                       4

<PAGE>

         liabilities and obligations of the Borrower or any of its Subsidiaries
         to any Lender in respect of cash management, depository accounts
         (including chargebacks) or similar agreements.

         (l)      The definition of "Restricted Payment" set forth in Section
1.1 of the Credit Agreement is hereby amended to read as follows:

                  "Restricted Payment" means (a) any Dividend; (b) any
                  redemption, conversion, exchange, retirement, sinking fund or
         similar payment, purchase or other acquisition for value, direct or
         indirect, of any shares of any class of Capital Stock of the Borrower
         or any of its Subsidiaries now or hereafter outstanding; (c) any
         payment or prepayment of principal of, premium, if any, or interest on,
         or any redemption, conversion, exchange, purchase, retirement or
         defeasance of, or payment with respect to, any Subordinated Debt; (d)
         any loan, advance or payment to any officer, director or shareholder of
         the Borrower or any of its Subsidiaries (other than a shareholder
         consisting of the Borrower or a Subsidiary of the Borrower), exclusive
         of reasonable compensation paid to officers or directors paid in the
         ordinary course of business; and (e) any payment made to retire, or to
         obtain the surrender of, any outstanding warrants, options or other
         rights to acquire shares of any class of Capital Stock of the Borrower
         or any of its Subsidiaries now or hereafter outstanding.

         (m)      The defined term "Third Amendment" is hereby added to Section
1.1 of the Credit Agreement in proper alphabetical order to read as follows:

                  "Third Amendment" means that certain Third Amendment to Third
         Amended and Restated Credit Agreement, dated as of May 30, 2003, among
         the Borrower, the Lenders, the Syndication Agent and the Administrative
         Agent.

         (n)      The defined term "Third Amendment Effective Date" is hereby
added to Section 1.1 of the Credit Agreement in proper alphabetical order to
read as follows:

                  "Third Amendment Effective Date" means the date that all of
         the conditions to effectiveness set forth in Section 3 of the Third
         Amendment have been satisfied.

         (o)      Section 2.3 Of the Credit Agreement is hereby amended to read
as follows:

                  Section 2.3 Repayment of Loans. The Borrower shall pay to the
         Administrative Agent for the account of each applicable Lender the
         principal of the Loans (including the Amortizing Loan Portion of the
         Loans) outstanding as of the Maturity Date (and the principal of the
         Loans outstanding as of the Maturity Date shall be due and payable) in
         full on the Maturity Date. In addition to the foregoing, the Borrower
         shall pay to the Administrative Agent for the account of each
         applicable Lender the outstanding principal of the Amortizing Loan
         Portion of the Loans in ten installments, as follows:

                                       5

<PAGE>

<TABLE>
<CAPTION>
   PAYMENT DATE                            PAYMENT AMOUNT
<S>                                        <C>
  July 31, 2003                              $1,375,000
 October 31, 2003                            $1,375,000
 January 31, 2004                            $1,375,000
  April 30, 2004                             $1,375,000
  July 31, 2004                              $1,375,000
 October 31, 2004                            $1,375,000
 January 31, 2005                            $1,375,000
  April 30, 2005                             $1,375,000
  July 31, 2005                              $1,375,000
November 30, 2005                            $  625,000
</TABLE>

         (p)      Section 2.10(a) of the Credit Agreement is hereby amended to
read as follows:

                  (a)    Subject to Section 13.12, the Borrower agrees to pay to
         the Administrative Agent for the account of each Lender a commitment
         fee on the daily average unused or unfunded amount of such Lender's
         Commitment, for the period from and including the Third Amendment
         Effective Date to and including the Revolving Period Termination Date,
         at the Applicable Margin for commitment fee calculated in accordance
         with the definition of "Applicable Margin" contained herein, based on a
         360-day year and the actual number of days elapsed, which accrued
         commitment fees shall be payable in arrears on each Quarterly Date and
         on the Revolving Period Termination Date.

         (q)      Section 2.14(b) of the Credit Agreement is hereby amended to
read as follows:

                  (b)    Prepayments from Excess Cash Flow. The Borrower shall,
         on or before October 31st of each year after the Third Amendment
         Effective Date if the ratio of Total Debt to EBITDA for the four fiscal
         quarters of the Borrower ended on the July 31st immediately preceding
         such October 31st is greater than or equal to 1.75 to 1.00, pay (or
         cause to be paid) to the Administrative Agent, as a prepayment of the
         Loans and the other Obligations then outstanding, an aggregate amount
         equal to fifty percent (50%) of the Excess Cash Flow for the fiscal
         year ended on the July 31st immediately preceding such payment date;
         provided, however that, for purposes of this Section 2.1(b), Excess
         Cash Flow attributable to the Canadian Subsidiaries generated on and
         after the Closing Date shall not exceed $2,000,000 in the aggregate.

         (r)      Section 9.4 of the Credit Agreement is hereby amended to read
as follows:

                  Section 9.4  Restricted  Payments. Each  of  the  Loan
         Parties will not, and will not permit any of its Subsidiaries to, make
         any Restricted Payments, except:

                  (a)   subject to the subordination provisions relating
         thereto, (i) the Borrower may make regularly scheduled payments of
         interest accrued on any Permitted Subordinated Debt and may pay
         principal of Permitted Subordinated Debt if and to the extent (but only
         if and to the extent) permitted by the express terms of the
         Subordinated Debt Documents governing such Permitted Subordinated Debt,
         which terms have been

                                       6

<PAGE>

expressly approved in writing by the Administrative Agent and (ii) Subsidiaries
of the Borrower may make payments of principal and interest accrued on
subordinated intercompany Debt which is permitted to be incurred in accordance
with Section 9.1(c) if and to the extent (but only if and to the extent) that
such payments are permitted by the terms of the documents governing such
subordinated intercompany Debt, which terms have been expressly approved in
writing by the Administrative Agent;

         (b)      Subsidiaries of the Borrower owned by the Borrower may declare
and pay Dividends to the Borrower to the extent permitted by applicable law;

         (c)      Subsidiaries of the Borrower owned by Subsidiaries of the
Borrower may declare and pay Dividends to their parent Subsidiaries to the
extent permitted by applicable law;

         (d)      the Borrower may purchase shares of Dynamex Common Stock from
employees of the Borrower or its Subsidiaries upon the termination of the
employment of such employees, provided that the amount paid therefor shall not
exceed the fair market value of such shares to be purchased and shall not exceed
$100,000 in the aggregate during any fiscal year;

         (e)      the Borrower and its Subsidiaries may make Loans to any
officer, director or shareholder of the Borrower or any of its Subsidiaries
(other than a shareholder consisting of the Borrower or a Subsidiary of the
Borrower) which, when aggregated with all such other loans, do not exceed
$100,000 in aggregate amount at any time outstanding; and

         (f)      the Borrower may declare and pay Dividends, provided that
prior to any declaration and payment of any such Dividend, the Borrower shall
have delivered to the Administrative Agent a Compliance Certificate calculated
on a pro-forma basis giving effect to the proposed Dividend which indicates that
the ratio of Total Debt to EBITDA for the four fiscal quarters ended immediately
preceding the date of such proposed Dividend is less than 1.75 to 1.00 and the
Fixed Charge Coverage Ratio for the four fiscal quarters ended immediately
preceding the date of such proposed Dividend is in compliance with Section 10.3;
provided, however, that no Restricted Payments may be made pursuant to clauses
(a), (d) or (f) preceding if a Default exists at the time of such Restricted
Payment or would result therefrom.

(s)      Section 10.1 of the Credit Agreement is hereby amended to read as
follows:

         Section 10.1 Maximum Ratio of Total Debt to EBITDA. The Borrower and
its consolidated Subsidiaries will not permit the ratio, calculated in
accordance with Section 1.4, of (i) Total Debt to (ii) EBITDA for the four
fiscal quarters of the Borrower then ended to be greater than (a) 2.25 to 1.00
at the end of any fiscal quarter of the Borrower up to and including July 31,
2003 and (b) 2.00 to 1.00 at the end of any fiscal quarter of the Borrower
thereafter.

(t)      Section 10.2 of the Credit Agreement is hereby amended to read as
follows:

                                       7

<PAGE>

                  Section 10.2 Minimum Net Worth. The Borrower and its
         consolidated Subsidiaries will at all times maintain Net Worth in an
         amount equal to (a) $45,000,000, plus (b) 75% of cumulative Net Income,
         if positive for any fiscal quarter (i.e., exclusive of any negative Net
         Income for any fiscal quarter), for any fiscal quarter commencing on
         and after May 1, 2003, plus (c) all Net Proceeds of each Equity
         Issuance which occurs on or after January 1, 2003.

         (u)      Exhibit I, the Form of Compliance Certificate, is hereby
amended to be in the form of Exhibit I hereto.

         2.       REPRESENTATIONS AND WARRANTIES TRUE; NO EVENT OF DEFAULT. By
its execution and delivery hereof, the Borrower represents and warrants that, as
of the date hereof, after taking into account the effectiveness of this Third
Amendment:

         (a)      the representations and warranties contained in the Credit
Agreement and the other Loan Documents are true and correct on and as of the
date hereof as made on and as of such date;

         (b)      no event has occurred and is continuing which constitutes a
Default or an Event of Default;

         (c)      (i) the Borrower has full power and authority to execute and
deliver this Third Amendment, the replacement Amortizing Loan Notes for each
Lender (the "Replacement Amortizing Loan Notes"), the replacement Revolving Loan
Notes for each Lender (the "Replacement Revolving Loan Notes") (collectively,
the "Replacement Notes"), (ii) this Third Amendment and the Replacement Notes
have been duly executed and delivered by the Borrower, and (iii) this Third
Amendment and the Replacement Notes and the Credit Agreement, as amended hereby,
constitute the legal, valid and binding obligations of the Borrower, enforceable
in accordance with their respective terms, except as enforceability may be
limited by applicable debtor relief laws and by general principles of equity
(regardless of whether enforcement is sought in a proceeding in equity or at
law) and except as rights to indemnity may be limited by federal or state
securities laws;

         (d)      neither the execution, delivery and performance of this Third
Amendment, the Replacement Notes or the Credit Agreement, as amended hereby, nor
the consummation of any transactions contemplated herein or therein, will
conflict with any Law or organizational documents of the Borrower, or any
indenture, agreement or other instrument to which the Borrower or any of its
property is subject; and

         (e)      no authorization, approval, consent, or other action by,
notice to, or filing with, any governmental authority or other Person not
previously obtained is required for the execution, delivery or performance by
the Borrower of this Third Amendment or the Replacement Notes.

         3.       CONDITIONS OF EFFECTIVENESS. This Third Amendment shall be
effective upon satisfaction of the following conditions:

         (a)      the representations and warranties set forth in Section 2 of
this Third Amendment shall be true and correct;

                                       8

<PAGE>

         (b)      the Administrative Agent shall have received counterparts of
this Third Amendment executed by the Lenders;

         (c)      the Administrative Agent shall have received counterparts of
this Third Amendment executed by the Borrower and acknowledged by each Loan
Party;

         (d)      the Administrative Agent shall have received duly executed
Replacement Notes for each Lender;

         (e)      Fleet shall have received $1,911,201.56, which represents
payment in full of all amounts due and owing to Fleet under the Credit Agreement
and the other Loan Documents;

         (f)      Bank Austria shall have received $1,146,720.86, which
represents payment in full of all amounts due and owing to Bank Austria under
the Credit Agreement and the other Loan Documents;

         (g)      the Administrative Agent shall have received payments in
respect of the Amortizing Loan Portion for the account of the Lenders such that
after giving effect thereto the outstanding aggregate amount of the Amortizing
Loan Portion is $13,000,000;

         (h)      the Administrative Agent shall have reviewed the Security
Documents and shall be satisfied with the results of such review; and

         (i)      the Administrative Agent shall have received in form and
substance satisfactory to the Administrative Agent, such other documents,
certificates and instruments as the Lenders shall require.

         4.       PURCHASE BY LENDERS. Simultaneously with the satisfaction of
conditions of effectiveness set forth in Section 3, each Lender shall purchase
or sell (as the case may be), without recourse, (a) an amount of loans
consisting of the Revolving Loan Portion and Letter of Credit liabilities
outstanding such that after giving effect to this Third Amendment, the amount of
each Lender's Commitment under the Credit Agreement which has been utilized
shall be pro rata among the Lenders in the proportion that their respective
Commitment bears to the aggregate Commitments and (b) an amount of the loans
consisting of the Amortizing Loan Portion outstanding such that after giving
effect to this Third Amendment, the Amortizing Loan Portion Percentage of each
Lender shall be a percentage based on the Amortizing Loan Portions set forth on
the signature pages hereto.

         5.       EXITING LENDERS. Upon satisfaction of the conditions set forth
in Section 3 of this Third Amendment, (a) no Exiting Lender shall (i) be a
Lender under the Credit Agreement or (ii) have any rights or obligations with
respect to being a Lender, except for those that expressly survive termination
of the Credit Agreement or termination of any commitments thereunder, (b) each
Exiting Lender shall mark its Revolving Loan Note and Amortizing Loan Note "PAID
IN FULL", and promptly return its Revolving Loan Note and Amortizing Loan Note
to the Borrower and (c) each Exiting Lender shall be entitled to the benefits of
Section 7 hereof. Fleet acknowledges and agrees that the amount set forth in
Section 3(e) above is all amounts due and owing to Fleet under the Credit
Agreement and the other Loan Documents. Bank Austria acknowledges and agrees
that the amount set forth in Section 3(f) above is all

                                       9

<PAGE>

amounts due and owing to Bank Austria under the Credit Agreement and the other
Loan Documents.

         6.       LOAN PARTY'S ACKNOWLEDGMENT. By signing below, each Loan Party
(i) acknowledges, consents and agrees to the execution, delivery and performance
by the Borrower of this Third Amendment, (ii) acknowledges and agrees that its
obligations in respect of the Loan Documents to which it is a party are not
released, diminished, waived, modified, impaired or affected in any manner by
this Third Amendment, or any of the provisions contemplated herein, (iii)
ratifies and confirms its obligations under the Loan Documents to which it is a
party, and (iv) acknowledges and agrees that it has no claim or offsets against,
or defenses or counterclaims to, its obligations under the Loan Documents to
which it is a party.

         7.       RELEASE. IN CONSIDERATION OF THE LENDER'S EXECUTION OF THIS
THIRD AMENDMENT, EACH OF THE LOAN PARTIES, IN EACH CASE ON BEHALF OF ITSELF AND
EACH OF THEIR SUCCESSORS AND ASSIGNS (COLLECTIVELY, THE "RELEASORS"), DOES
VOLUNTARILY AND KNOWINGLY RELEASE AND FOREVER DISCHARGE EACH LENDER, EACH
EXITING LENDER AND ADMINISTRATIVE AGENT AND THEIR RESPECTIVE PREDECESSORS,
OFFICERS, DIRECTORS, EMPLOYEES, AGENTS, SUCCESSORS AND ASSIGNS (EACH, A
"RELEASED PARTY") FROM ALL POSSIBLE CLAIMS, DEMANDS, ACTIONS, CAUSES OF ACTION,
DAMAGES, COSTS, EXPENSES, AND LIABILITIES WHATSOEVER, KNOWN OR UNKNOWN,
ANTICIPATED OR UNANTICIPATED, SUSPECTED OR UNSUSPECTED, FIXED, CONTINGENT, OR
CONDITIONAL, AT LAW OR IN EQUITY, ARISING ON OR BEFORE THE DATE THIS THIRD
AMENDMENT IS EXECUTED, WHICH BORROWER OR ANY LOAN PARTY MAY NOW HAVE AGAINST ANY
RELEASED PARTY, IF ANY, AND IRRESPECTIVE OF WHETHER ANY SUCH CLAIMS ARISE OUT OF
CONTRACT, TORT, VIOLATION OF LAW OR REGULATIONS, OR OTHERWISE, AND ARISING FROM
ANY "OBLIGATIONS", INCLUDING, WITHOUT LIMITATION, ANY CONTRACTING FOR, CHARGING,
TAKING, RESERVING, COLLECTING OR RECEIVING INTEREST IN EXCESS OF THE HIGHEST
LAWFUL RATE APPLICABLE, THE EXERCISE OF ANY RIGHTS AND REMEDIES UNDER THE CREDIT
AGREEMENT OR OTHER LOAN DOCUMENTS, AND NEGOTIATION FOR AND EXECUTION OF THIS
THIRD AMENDMENT.

         8.       REFERENCE TO THE CREDIT AGREEMENT.

         (a)      Upon and during the effectiveness of this Third Amendment,
each reference in the Credit Agreement to "this Agreement", "hereunder", or
words of like import shall mean and be a reference to the Credit Agreement, as
affected by this Third Amendment.

         (b)      Except as expressly set forth herein, this Third Amendment
shall not by implication or otherwise limit, impair, constitute a waiver of, or
otherwise affect the rights or remedies of the Administrative Agent or the
Lenders under the Credit Agreement or any of the other Loan Documents, and shall
not alter, modify, amend, or in any way affect the terms, conditions,
obligations, covenants, or agreements contained in the Credit Agreement or the
other

                                       10

<PAGE>

Loan Documents, all of which are hereby ratified and affirmed in all respects
and shall continue in full force and effect.

         9.       COSTS AND EXPENSES. The Borrower shall be obligated to pay the
costs and expenses of the Administrative Agent in connection with the
preparation, reproduction, execution and delivery of this Third Amendment and
the other instruments and documents to be delivered hereunder.

         10.      EXECUTION IN COUNTERPARTS. This Third Amendment may be
executed in any number of counterparts and by different parties hereto in
separate counterparts, each of which when so executed and delivered shall be
deemed to be an original and all of which when taken together shall constitute
but one and the same instrument. For purposes of this Third Amendment, a
counterpart hereof (or signature page thereto) signed and transmitted by any
Person party hereto to the Administrative Agent (or its counsel) by facsimile
machine, telecopier or electronic mail is to be treated as an original. The
signature of such Person thereon, for purposes hereof, is to be considered as an
original signature, and the counterpart (or signature page thereto) so
transmitted is to be considered to have the same binding effect as an original
signature on an original document.

         11.      GOVERNING LAW; BINDING EFFECT. This Third Amendment shall be
governed by and construed in accordance with the laws of the State of Texas
(without giving effect to conflict of laws) and the United States of America,
and shall be binding upon the Borrower and each Lender and their respective
successors and assigns.

         12.      HEADINGS. Section headings in this Third Amendment are
included herein for convenience of reference only and shall not constitute a
part of this Third Amendment for any other purpose.

         13.      ENTIRE AGREEMENT. THE CREDIT AGREEMENT, AS AMENDED BY THIS
THIRD AMENDMENT, AND THE OTHER LOAN DOCUMENTS REPRESENT THE FINAL AGREEMENT
BETWEEN THE PARTIES AS TO THE SUBJECT MATTER THEREIN AND HEREIN AND MAY NOT BE
CONTRADICTED BY EVIDENCE OF PRIOR, CONTEMPORANEOUS, OR SUBSEQUENT ORAL
AGREEMENTS BETWEEN THE PARTIES.

================================================================================
                   REMAINDER OF PAGE LEFT INTENTIONALLY BLANK
================================================================================

                                       11

<PAGE>

         IN WITNESS WHEREOF, the parties hereto have executed this Third
Amendment as of the date first above written.

                                DYNAMEX INC.

                                By: /s/ Ray Schmitz
                                    --------------------------------------------
                                    Name:  Ray E. Schmitz
                                    Title: Vice President & CFO

                                DYNAMEX OPERATIONS EAST, INC.
                                DYNAMEX OPERATIONS WEST, INC.
                                ROAD RUNNER TRANSPORTATION, INC.
                                NEW YORK DOCUMENT EXCHANGE CORPORATION
                                DYNAMEX DEDICATED FLEET SERVICES, INC.
                                DYNAMEX CANADA HOLDINGS, INC.
                                DYNAMEX PROVINCIAL COURIERS, INC.
                                DYNAMEX CANADA HOLDINGS NS CORP.
                                DYNAMEX PROVINCIAL COURIERS NS
                                      CORP., individually and as general partner
                                      of Dynamex Canada Limited Partnership
                                DYNAMEX CANADA CORP.
                                ALPINE ENTERPRISES LTD.

                                By: /s/ Ray Schmitz
                                    --------------------------------------------
                                    Name:  Ray E. Schmitz
                                    Title: Vice President & CFO

                                ADMINISTRATIVE AGENT:

                                BANK OF AMERICA, N.A.,
                                as Administrative Agent

                                By: /s/ Suzanne M. Paul
                                    --------------------------------------------
                                    Name:  Suzanne M. Paul
                                    Title: Vice President

                                        12

<PAGE>
                                LENDERS:

                                BANK OF AMERICA, N.A.
COMMITMENT: $14,677,304

AMORTIZING LOAN PORTION:
$8,574,822
                                By: /s/ Michael F. Murray
                                    --------------------------------------------
                                    Name:  Michael F. Murray
                                    Title: Vice President

                                BANK ONE, N.A., (Main Office Chicago)
                                as Syndication Agent and as a Lender

COMMITMENT: $4,822,696

AMORTIZING LOAN PORTION:
$4,425,178

                                By: /s/ Sharon Ellis
                                    --------------------------------------------
                                    Name:  Sharon Ellis
                                    Title: Vice President

ACKNOWLEDGED AND AGREED
FOR PURPOSES OF SECTION 5 AND
SECTION 7 HEREOF ONLY:

FLEET NATIONAL BANK

By: /s/ Kay H. Campbell
    ----------------------------
    Name:  Kay H. Campbell
    Title: Vice President

                                       13

<PAGE>

BANK AUSTRIA CREDITANSTALT
CORPORATE FINANCE, INC.

By: /s/ Scott Obeck
    ----------------------------
    Name:  Scott Obeck
    Title: Associate Director

By: /s/ Warren Seidel
    ----------------------------
    Name:  Warren Seidel
    Title: Senior Vice President

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