Exhibit 32

Certification of CEO and CFO Pursuant to 18 U.S.C. Section 1350 as adopted

pursuant to Section 906 of the Sarbanes-Oxley Act of 2002

      In connection with the Quarterly Report of Swift Transportation Co., Inc. (the “Company”) for the period ended March 31, 2006 as filed on Form 10-Q with the Securities and Exchange Commission on the date hereof (the “Report”), each of the undersigned certifies, pursuant to 18 U.S.C. section 1350, as adopted pursuant to section 906 of the Sarbanes-Oxley Act of 2002, that to the best of his or her knowledge:

      (1) The Report fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

      (2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

/s/ Robert W. Cunningham

Robert W. Cunningham

Chief Executive Officer and President

(Principal Executive Officer)

/s/ Glynis Bryan

Glynis Bryan

Chief Financial Officer

(Principal Financial Officer)

Date: May 9, 2006

      This certification is being furnished pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 and shall not be deemed filed by the Registrant as part of the Quarterly Report on Form 10-Q.

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