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                                                             Exhibit 10.18

                              SEPARATION AGREEMENT

      This Separation Agreement ("Agreement") is made and entered into by and
between Kevin H. Jensen ("Employee") and Swift Transportation Co. Inc., its
subsidiaries, related companies, business affiliates and the directors,
officers, employees, agents, and successors of such entities (the "Company").

      1. Employee agrees to voluntarily terminate his employment with the
Company effective on June 24, 2005. Twelve (12) business days after receiving a
fully executed original of this Agreement from Employee (i) the Company will pay
Employee (by U.S. Mail) a check in the gross amount of $140,843 ($65,843 of
which is reimbursement of expenses incurred by Employee for which Employee has
provided receipts) less applicable withholdings and (ii) the Company will
forgive the Employee's indebtedness to the Company in the amount of $231,915 the
full amount of which will be recognized as taxable income to Employee; provided
that Employee has not revoked this Agreement as provided in Paragraph 4(G),
below. Employee agrees that the foregoing constitutes the entire amount of
monetary consideration provided to Employee under this Agreement.

      2. Employee represents that he has not filed any complaints, claims, or
actions against the Company, its officers, agents, directors, employees, or
representatives with any state, federal, or local agency or court and that
Employee will not do so at any time hereafter and that if any agency or court
assumes jurisdiction of any complaint, claim, or action against the Company or
its affiliated companies or any of their officers, agents, directors, employees,
or representatives on behalf of Employee, Employee will direct that agency or
court to withdraw from or dismiss with prejudice the matter as to any claim made
by Employee or on Employee's behalf.

      3. Employee hereby irrevocably and unconditionally releases and forever
discharges the Company and each and all of its officers, agents, directors,
employees, representatives, and their successors and assigns and all persons
acting by, through, under, or in concert with any of them from any and all
charges, complaints, claims, grievances, actions, and liabilities of any kind or
nature whatsoever, known or unknown, suspected or unsuspected (hereinafter
referred to as "claim" or "claims") which Employee at any time heretofore had or
claimed to have or which Employee may have or claim to have regarding events
that have occurred as of the date of this Agreement, including, without
limitation, any and all claims related or in any manner incidental to Employee's
employment with the Company or the termination therefrom or otherwise. All such
claims (including related attorneys' fees and costs) are forever barred by this
Agreement regardless of whether those claims are based on any alleged breach of
a duty arising in a statute, contract, or tort; any alleged unlawful act,
including, without limitation, discrimination or harassment of any kind; any
other claim or cause of action; and regardless of the forum in which it might be
brought.

      4. Employee hereby represents and agrees he:

            A.    has reviewed all aspects of this Agreement;

            B.    has carefully read and fully understands all the provisions of
                  this Agreement;
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            C.    understands that in agreeing to this document he is releasing
                  the Company from any and all claims he may have against the
                  Company;

            D.    knowingly and voluntarily agrees to all the terms set forth in
                  this Agreement;

            E.    was advised and hereby is advised in writing to consider the
                  terms of this Agreement and that he may consult with an
                  attorney of his choice prior to executing this Agreement;

            F.    has a full twenty-one (21) days from the date of termination
                  to consider whether he will execute this Agreement;

            G.    has a full seven (7) days following the execution of this
                  Agreement to revoke the Agreement and has been and hereby is
                  advised in writing that this Agreement shall not become
                  effective or enforceable until the revocation period has
                  expired; and

            H.    understands that rights or claims under the Age Discrimination
                  in Employment Act of 1967 (29 U.S.C.Section 621, et seq.) that
                  may arise after the date of this Agreement is executed are not
                  waived.

      5. Employee further represents and agrees that he does not rely and has
not relied upon any representation or statement made by Company other than those
specifically stated in this written Agreement.

      6. Employee agrees that he will not seek employment with the Company in
the future and that the Company is entitled to reject without cause any
application for employment with the Company made by Employee.

      7. Employee agrees to keep the terms and amount of this Agreement
completely confidential and Employee will not disclose any information
concerning this Agreement to anyone other than his family or advisors, provided
that he may make such disclosures as required by law or necessary for legitimate
law enforcement or compliance purposes.

      8. This Agreement shall be binding upon the parties hereto and upon their
heirs, administrators, representatives, executors, successors, and assigns, and
shall inure to the benefit of said parties and each of them and to their heirs,
administrators, representatives, executors, successors, and assigns. Employee
expressly warrants that he has not transferred to any person or entity any
rights, causes of action, or claims released in this Agreement.

      9. This Agreement shall not be construed as an admission by the Company of
any liability or wrongdoing whatsoever.

      10. Employee agrees to comply with the terms of the Company's Securities
Trading Policy in all respects, including in connection with his possible
exercise and sale of vested stock options. Employee acknowledges that a
"Blackout Period" currently covers Employee, which period will not be cleared
until, at the earliest, two (2) full

                                       2
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trading days after the Company publicly releases earnings for the second
quarter. The Company currently expects to release second quarter earnings on
July 18, 2005.

      11. This Agreement sets forth the entire agreement between the parties
hereto and fully supersedes any and all prior agreements or understandings,
written or oral, between the parties. This Agreement shall be interpreted in
accordance with the plain meaning of its terms and not strictly for or against
any of the parties. The parties agree that this Agreement is entered into under
applicable state law and it shall be construed and governed under the laws of
the State of Arizona. Should any provision of this Agreement be declared or be
determined by any court of competent jurisdiction to be wholly or partially
illegal, invalid, or unenforceable, the legality, validity, and enforceability
of the remaining parts, terms, or provisions shall not be affected thereby, and
said illegal, unenforceable, or invalid part, term, or provision shall be deemed
not to be a part of this Agreement.

      12. Any dispute arising under this Agreement shall be determined by final
and binding arbitration under AAA Employment Dispute Resolution Rules. The
arbitrator shall be selected by mutual agreement of the parties. If the parties
are unable to agree on an arbitrator within ten (10) days, the Arbitrator shall
be chosen pursuant to American Arbitration Association's Employment Dispute
Resolution Rules. All parties waive all rights to proceed in court or other
forum.

      13. Employee warrants that he has returned to the Company all Company
property, including computers, telephones, pagers and all proprietary
information, including, but not limited to, memoranda, books, papers, letters,
formulae, computer data, disks, manuals, price information, order forms, client
lists, customer pricing, contract terms, supplier lists, and other data (and all
copies thereof or therefrom) in any way relating to the Company's business and
affairs. Employee further agrees to keep confidential for a period of five (5)
years from the date of this Agreement all trade secrets, proprietary
information, and other confidential information of the Company that is not
publicly available.

      14. This Agreement consists of three (3) pages.

EMPLOYEE                                   COMPANY

                                           By:
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                                           Title:
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