July 29, 2003


Smithway Motor Xpress, Inc.
2031 Quail Avenue
Fort Dodge, Iowa 50501

And

East West Motor Express, Inc.
1170 JB Drive
Black Hawk, South Dakota 57718

Re:  Sixth Amendment to Amended and Restated Loan and
     Security Agreement

Gentlemen:

     Smithway Motor Xpress, Inc., an Iowa corporation ("Smithway Inc.") and East
West Motor Express,  Inc., a South Dakota  corporation  ("East West")  (Smithway
Inc. and East West each a  "Borrower"  and  collectively  the  "Borrowers")  and
LaSalle Bank National Association,  a national banking association ("Bank") have
entered into that certain Amended and Restated Loan and Security Agreement dated
December  28, 2001 (the  "Security  Agreement").  From time to time  thereafter,
Borrowers and Bank may have executed various amendments (each an "Amendment" and
collectively the "Amendments") to the Security Agreement (the Security Agreement
and  the  Amendments   hereinafter  are  referred  to,   collectively,   as  the
"Agreement").  Borrowers  and Bank now desire to further  amend the Agreement as
provided herein, subject to the terms and conditions hereinafter set forth.

     NOW,  THEREFORE,  in  consideration of the foregoing  recitals,  the mutual
covenants  and   agreements  set  forth  herein  and  other  good  and  valuable
consideration, the receipt and sufficiency of which are hereby acknowledged, the
parties hereto hereby agree as follows:

     1. The Agreement hereby is amended as follows:

     (a) The  definition of "Maximum Loan Limit" set forth in Paragraph 1 of the
Agreement  is deleted in its entirety and the  following is  substituted  in its
place:

          "Maximum  Loan Limit"  shall mean  Twenty-Seven  Million  Five Hundred
          Thousand and No/100 Dollars ($27,500,000.00).

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Smithway Motor Xpress, Inc.
East West Motor Express, Inc.
July 29, 2003
Page 2

     (b)  Subsection  2(a) of the  Agreement  is deleted in its entirety and the
following is substituted in its place:

          2. LOANS.

          (a) Revolving Loans.

     Subject  to the  terms  and  conditions  of this  Agreement  and the  Other
Agreements,  during the Original Term and any Renewal Term, Lender shall, absent
the  occurrence  of an Event of Default,  make  revolving  loans and advances to
Borrowers' (the  "Revolving  Loans") in an amount up to the sum of the following
sublimits (the "Revolving Loan Limit"):


     (i)  Up  to  eighty-five  percent  (85%),  or  such  lesser  percentage  as
determined by Lender in its sole  discretion  determined  in good faith,  of the
face amount (less maximum  discounts,  credits and allowances which may be taken
by or granted to Account Debtors in connection  therewith in the ordinary course
of Borrowers'  business) of Borrowers'  Eligible Accounts  (consisting solely of
Eligible  Accounts  other than those set forth at  subsection  (ii)  immediately
below); plus

     (ii)  Up to  eighty-five  percent  (85%),  or  such  lesser  percentage  as
determined by Lender in its sole  discretion  determined  in good faith,  of the
face amount (less maximum  discounts,  credits and allowances which may be taken
by or granted to Account Debtors in connection  therewith in the ordinary course
of Borrowers'  business) of Borrowers'  Eligible Accounts  (consisting solely of
Accounts  which are  unbilled  for three (3) days or less) or Two  Million  Five
Hundred Thousand and No/100 Dollars ($2,500,000.00), whichever is less; plus

     (iii) Intentionally Omitted; minus

     (iv) such reserves as Lender elects,  in its sole discretion  determined in
good faith to establish from time to time;

provided,  that the Revolving  Loan Limit shall in no event exceed  Twenty-Seven
Million  Five  Hundred  Thousand and No/100  Dollars  ($27,500,000.00)  less the
then-outstanding  principal  balance of the Term Loans (the  "Maximum  Revolving
Loan Limit") except as such amount may be increased or, following the

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Smithway Motor Xpress, Inc.
East West Motor Express, Inc.
July 29, 2003
Page 3

occurrence of an Event of Default, decreased by Lender, in its sole discretion.

     The aggregate unpaid principal  balance of the Revolving Loans shall not at
any time exceed the lesser of the (i)  Revolving  Loan Limit minus the Letter of
Credit Obligations and (ii) the Maximum Revolving Loan Limit minus the Letter of
Credit  Obligations.  If at any time the  outstanding  Revolving  Loans  exceeds
either the Revolving  Loan Limit or the Maximum  Revolving  Loan Limit,  in each
case minus the Letter of Credit  Obligations,  or any  portion of the  Revolving
Loans and Letter of Credit  Obligations  exceeds any applicable  sublimit within
the Revolving Loan Limit, Borrowers shall immediately, and without the necessity
of demand by Lender,  pay to Lender such amount as may be necessary to eliminate
such  excess  and Lender  shall  apply such  payment to the  Revolving  Loans to
eliminate such excess.

     Each Borrower hereby authorizes  Lender, in its sole discretion,  to charge
any of such Borrower's  accounts or advance Revolving Loans to make any payments
of principal,  interest,  fees, costs or expenses required to be made under this
Agreement or the Other Agreements.

     A request for a Revolving Loan shall be made or shall be deemed to be made,
each in the following manner: the Borrower  requesting such Revolving Loan shall
give Lender same day notice,  no later than 10:30 A.M.  (Chicago  time) for such
day, of its request for a Revolving Loan as a Prime Rate Loan. In the event that
a Borrower  maintains a controlled  disbursement  account at Lender,  each check
presented for payment against such controlled disbursement account and any other
charge or request for payment against such controlled disbursement account shall
constitute  a  request  for  a  Revolving  Loan  as a  Prime  Rate  Loan.  As an
accommodation to Borrowers,  Lender may permit telephone  requests for Revolving
Loans and electronic transmittal of instructions,  authorizations, agreements or
reports to Lender by Borrowers. Unless a Borrower specifically directs Lender in
writing not to accept or act upon telephonic or electronic  communications  from
such  Borrower,  Lender shall have no  liability  to  Borrowers  for any loss or
damage suffered by a Borrower as a result of Lender's  honoring of any requests,
execution of any  instructions,  authorizations or agreements or reliance on any

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Smithway Motor Xpress, Inc.
East West Motor Express, Inc.
July 29, 2003
Page 4

reports  communicated to it telephonically  or electronically  and purporting to
have been sent to Lender by a Borrower  and Lender  shall have no duty to verify
the origin of any such communication or the authority of the Person sending it.

     Each Borrower hereby irrevocably authorizes Lender to disburse the proceeds
of each Revolving Loan requested by such Borrower,  or deemed to be requested by
such Borrower,  as follows:  the proceeds of each Revolving Loan requested under
Section 2(a) shall be  disbursed by Lender in lawful money of the United  States
of America  in  immediately  available  funds,  by wire  transfer  or  Automated
Clearing House (ACH) transfer to such bank account as may be agreed upon by such
Borrower  and Lender from time to time,  or  elsewhere  if pursuant to a written
direction from such Borrower.

     (c)  Subsection  4(b) of the  Agreement  is deleted in its entirety and the
following is substituted in its place:

          (iv) One-Time Fee: Borrowers shall pay to Lender a one-time fee of Ten
               Thousand  and  No/100  Dollars  ($10,000.00),  which fee shall be
               fully earned and payable upon execution of this Amendment.

     (d)  Section  10 of the  Agreement  is  deleted  in its  entirety  and  the
following is substituted in its place:

          10.  TERMINATION: AUTOMATIC RENEWAL.

               THIS  AGREEMENT  SHALL  BE  IN  EFFECT  UPON  EXECUTION  OF  THIS
               AMENDMENT  UNTIL  JULY 1, 2004 (THE  "ORIGINAL  TERM")  AND SHALL
               AUTOMATICALLY  RENEW ITSELF FROM MONTH TO MONTH  THEREAFTER (EACH
               SUCH  ONE-MONTH  RENEWAL  BEING  REFERRED TO HEREIN AS A "RENEWAL
               TERM") unless (A) THE DUE DATE OF THE  LIABILITIES IS ACCELERATED
               PURSUANT TO SECTION 16 HEREOF; OR (B) A BORROWER OR LENDER ELECTS
               TO TERMINATE THIS AGREEMENT AT THE END OF THE ORIGINAL TERM OR AT
               THE END OF ANY  RENEWAL  TERM BY GIVING THE OTHER  PARTY  WRITTEN
               NOTICE OF SUCH  ELECTION AT

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Smithway Motor Xpress, Inc.
East West Motor Express, Inc.
July 29, 2003
Page 5

               LEAST  FIFTEEN (15) DAYS PRIOR TO THE END OF THE ORIGINAL TERM OR
               THE THEN CURRENT  RENEWAL TERM IN WHICH CASE BORROWERS  SHALL PAY
               ALL OF THE  LIABILITIES  IN FULL ON THE LAST DAY OF SUCH TERM. If
               one or  more  of the  events  specified  in  clauses  (a) and (b)
               occurs, then (i) Lender shall not make any additional Loans on or
               after the date  identified  as the date on which the  Liabilities
               are to be repaid;  and (ii) this Agreement shall terminate on the
               date  thereafter  that the  Liabilities are paid in full. At such
               time as  Borrowers  have repaid all of the  Liabilities  and this
               Agreement  has  terminated,  Borrowers  shall deliver to Lender a
               release,  in form and substance  satisfactory  to Lender,  of all
               obligations   and   liabilities   of  Lender  and  its  officers,
               directors,   employees,   agents,   parents,   subsidiaries   and
               affiliates to such Borrowers,  and if Borrowers are obtaining new
               financing  from  another  lender,  Borrowers  shall  deliver such
               lender's   indemnification  of  Lender,  in  form  and  substance
               satisfactory  to Lender,  for checks which Lender has credited to
               such Borrower's  account,  but which  subsequently are dishonored
               for any reason or for automatic  clearinghouse  or wire transfers
               not yet posted to such Borrower's account.

     (e) Exhibit A of the Agreement is amended and restated as the First Amended
and Restated Exhibit A as attached hereto and made a part hereof.

     2. This Amendment  shall not become  effective  until fully executed by all
parties hereto.

     3.  Except  as  expressly  amended  hereby  and by any  other  supplemental
documents or instruments  executed by either party hereto in order to effectuate
the transactions contemplated hereby, the Agreement and Exhibit A thereto hereby
are  ratified and  confirmed by the parties  hereto and remain in full force and
effect in accordance with the terms thereof.

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Smithway Motor Xpress, Inc.
East West Motor Express, Inc.
July 29, 2003
Page 6

                                 LASALLE BANK NATIONAL ASSOCIATION

                                 By  /s/ John Mostofi
                                   ---------------------------------
                                 Title    Sr VP
                                      ------------------------------

ACKNOWLEDGED AND AGREED TO
this 31st day of July, 2003:

SMITHWAY MOTOR XPRESS, INC.

By    /s/ William G. Smith
  -----------------------------------
     William G. Smith

Title President

EAST WEST MOTOR EXPRESS, INC.

By    /s/ William G. Smith
  -----------------------------------
     William G. Smith

Title President

Consented and agreed to by the
following  guarantor(s)  of the
obligations  of  Smithway  Motor
Xpress,  Inc.  and East West
Motor Express, Inc. to
LaSalle Bank National Association.

SMSD Acquisition Corp.

By:   /s/ G. Larry Owens
  -----------------------------------
     G. Larry Owens

Title: Vice President

Date: July 31st, 2003


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Smithway Motor Xpress, Inc.
East West Motor Express, Inc.
July 29, 2003
Page 7


Smithway Motor Xpress Corp.

By:   /s/ G. Larry Owens
  -----------------------------------
     G. Larry Owens

Title: Vice President

Date: July 31st, 2003




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Exhibits available upon request.