MARTEN TRANSPORT LTD 10-Q

Item 1A. Risk Factors.   There have been no material changes in the risk factors disclosed by us under Part I, Item 1A. Risk Factors contained in the Annual Report on Form 10-K for the year ended December 31, 2022.   Item 6. Exhibits.   Item No. Item   Method of Filing 31.1 Certification pursuant to Item 601(b)(31) of Regulation S-K, as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002, by Timothy M. Kohl, the Registrant’s Chief Executive Officer (Principal Executive Officer)   Filed with this Report.         31.2 Certification pursuant to Item 601(b)(31) of Regulation S-K, as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002, by James J. Hinnendael, the Registrant’s Executive Vice President and Chief Financial Officer (Principal Financial Officer)   Filed with this Report.         32.1 Certification pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002   Filed with this Report.         101 The following financial information from Marten Transport, Ltd.’s Quarterly Report on Form 10-Q for the period ended March 31, 2023, filed with the SEC on May 5, 2023, formatted in iXBRL, or Inline eXtensible Business Reporting Language: (i) Consolidated Condensed Balance Sheets, (ii) Consolidated Condensed Statements of Operations, (iii) Consolidated Condensed Statements of Stockholders’ Equity, (iv)  Consolidated Condensed Statements of Cash Flows, and (v) Notes to Consolidated Condensed Financial Statements   Filed with this Report.         104 The cover page from Marten Transport, Ltd.’s Quarterly Report on Form 10-Q for the period ended March 31, 2023, formatted in iXBRL, included in Exhibit 101   Filed with this Report.   19     SIGNATURES   Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this Report to be signed on its behalf by the undersigned, thereunto duly authorized.     MARTEN TRANSPORT, LTD.             Dated: May 5, 2023 By: /s/ Timothy M. Kohl     Timothy M. Kohl     Chief Executive Officer     (Principal Executive Officer)             Dated: May 5, 2023 By: /s/ James J. Hinnendael     James J. Hinnendael     Executive Vice President and Chief Financial Officer     (Principal Financial and Accounting Officer)   20