<PAGE>   1
                                                                   EXHIBIT 10.26




                 FIFTH AMENDMENT, WAIVER AND OVERRIDE AGREEMENT

          FIFTH AMENDMENT, WAIVER AND OVERRIDE AGREEMENT, dated as of February
14, 2001 (this "Amendment"), to the Credit Agreement, dated as of August 11,
1999 (as amended, supplemented or otherwise modified prior to the date hereof,
the "Existing Credit Agreement"; as modified hereby and as further amended,
supplemented or otherwise modified from time to time, the "Credit Agreement"),
among CELADON GROUP, INC., a Delaware corporation ("Group") and CELADON TRUCKING
SERVICES, INC., a New Jersey corporation ("Trucking"; together with Group, each
a "Borrower", collectively, the "Borrowers") the banks and other financial
institutions parties thereto (the "Lenders"), and ING (U.S.) CAPITAL LLC, as
administrative agent (the "Administrative Agent") and arranger for the Lenders.

                                    RECITALS

          The Borrowers have requested that the Administrative Agent and the
Lenders agree to amend, waive and override certain provisions of the Credit
Agreement as set forth in this Amendment. The Administrative Agent and the
Lenders parties hereto are willing to agree to such amendments, waivers and
override provisions, but only on the terms and subject to the conditions set
forth herein.

          NOW, THEREFORE, in consideration of the premises and for other good
and valuable consideration, the receipt and sufficiency of which is hereby
acknowledged, the Borrowers, the Administrative Agent and the Lenders hereby
agree as follows:

          1. Defined Terms. Unless otherwise defined herein, terms defined in
the Credit Agreement are used herein as therein defined.

          2. Amendments. Section 1.1 of the Existing Credit Agreement is hereby
amended by deleting the following definitions and substituting in lieu thereof
the following new definitions, to read in their entirety as follows:

          "Applicable Margin": (a) for any Term Loan or any Revolving Credit
Loan of any Type, during the period commencing on the Closing Date and ending on
the date on which the Administrative Agent receives the financial statements of
Group for the fiscal quarter ending September 30, 1999 in accordance with
Section 8.1(b), the rate per annum set forth under the relevant column heading
below:


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          -------------------------------------------------
                Base Rate Loans        Eurodollar Loans
          -------------------------------------------------
                    1.00%                   2.00%
          -------------------------------------------------

          (b) for any Term Loan or Revolving Credit Loan of any Type at any time
following the date on which the Administrative Agent receives the financial
statements of Group for the fiscal quarter ending September 30, 1999 in
accordance with Section 8.1(b) on which the Leverage Ratio, as most recently
determined as of the date the certificate containing such Leverage Ratio is
delivered pursuant to Section 8.2(b), is within any of the ranges set forth
below, the rate per annum set forth under the relevant column heading opposite
the applicable range below; provided, that any changes in such rate shall be
effective as of the date which is five (5) days following the date on which the
certificate containing such Leverage Ratio is delivered:


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          -------------------------------------------------------------------
               Leverage Ratio         Base Rate Loans      Eurodollar Loans
          -------------------------------------------------------------------
             Greater than 4.50            2.00%                 3.00%
          -------------------------------------------------------------------
           Less than or equal to          1.75%                 2.75%
           4.50 but greater
              than 4.25
          -------------------------------------------------------------------
           Less than or equal to          1.50%                 2.50%
           4.25 but greater
              than 4.0
          -------------------------------------------------------------------
           Less than or equal to          1.25%                 2.25%
           4.0 but greater
              than 3.5
          -------------------------------------------------------------------
           Less than or equal to          1.00%                 2.00%
           3.5 but greater
              than 3.0
          -------------------------------------------------------------------
           Less than or equal to          0.75%                 1.75%
           3.0 but greater
              than 2.5
          -------------------------------------------------------------------
           Less than or equal             0.50%                 1.50%
               to 2.5
          -------------------------------------------------------------------

provided, that in the event that the certificate containing the determination of
the Leverage Ratio is not delivered by the date specified and otherwise in
accordance with to Section 8.2(b) hereof, the applicable margin shall be the
highest rate per annum for such Type of Loan set forth above from the date on
which such certificate was required to be delivered in accordance with Section
8.2(b) until such time as such certificate is delivered to the Lenders; and
provided further, that in calculating the Leverage Ratio for the purposes of
determining the Applicable Margin, the financial performance of TruckersB2B.com,
Inc. shall be included.

          "Borrowing Base": at any time, the sum of (a) 85% (or such other
percentage as the Administrative Agent or the Required Lenders shall determine
in accordance with Section 8.9) of the then Eligible Domestic Accounts, (b) 65%
(or such other percentage as the Administrative Agent or the Required Lenders
shall determine in accordance with Section 8.9) of Eligible Mexican Accounts,
(c) 80% (or such other percentage as the Administrative Agent or the Required
Lenders shall determine in accordance with Section 8.9) of Eligible Canadian
Accounts; provided, that in no event shall the collateral value of Eligible
Canadian Accounts included in the Borrowing Base at any time exceed $6,000,000,
and (d) the following percentages (or such other percentages as the
Administrative Agent or the Required Lenders shall determine in accordance with
Section 8.9) of the net book value of all Eligible Tires for the following
periods: (i) through December 31, 2000, 90%; through January 31, 2001, 70%;


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through February 28, 2001, 60%; through March 31, 2001, 50%; through April 30,
2001, 40%; through May 31, 2001, 30%; through June 30, 2001, 20%; through July
31, 2001, 10%, and thereafter, 0%. The Borrowing Base in effect at any time
shall be the Borrowing Base as shown on the Borrowing Base Certificate most
recently delivered by the Borrowers pursuant to this Agreement; provided,
however, that if the Borrowers shall fail to deliver a Borrowing Base
Certificate when required pursuant to Section 8.2(c), the Borrowers shall not be
permitted to make any new borrowings hereunder until such Borrowing Base
Certificate is delivered and, from and after the date which is five (5) days
following the date on which such Borrowing Base Certificate was required to be
delivered pursuant to 8.2(c), the Borrowing Base in effect shall be zero until
such Borrowing Base Certificate is delivered.

          3. Waivers. Each of the Administrative Agent and the Lenders hereby
waive any Default or Events of Default resulting from the Borrowers' failure to
comply with Section 9.1(b) (Interest Coverage) and Section 9.1(c) (Minimum Fixed
Charge Coverage) of the Existing Credit Agreement for the period of four fiscal
quarters ended December 31, 2000.

          4. Override Provisions.

     (a)  Notwithstanding the provisions of Section 5.5 of the Existing Credit
Agreement, (i) in the event that the Borrowers effectuate a refinancing of the
property located at 15200 South State Road 11, Jonesville, Indiana, the first
$1.5 million of net proceeds of such refinancing shall be applied to prepay
installments of principal of the Terms Loans in inverse order of maturity, and
the balance of such net proceeds shall be applied to repay Revolving Credit
Loans, and (ii) in the event that the Borrowers effectuate a sale of Cheetah
Transportation Co. and/or Cheetah Brokerage Co., the first $3.5 million of net
proceeds of such sale shall be applied to prepay installments of principal of
the Terms Loans in inverse order of maturity, and the balance of such net
proceeds shall be applied to repay Revolving Credit Loans.

     (b)  Notwithstanding the provisions of Sections 9.5, 9.9 and 9.11 the
Credit Agreement, in the event that TruckersB2B.Com, Inc. does not have
Consolidated EBITDA of at least $1.00 for the month ended May 31, 2001 or for
any month thereafter, none of Group, any Borrower or any Subsidiary of any
Borrower may thereafter make any loans or advances to, or merger with or into,
or enter into any other transaction with, TruckersB2B.Com, Inc. Beginning with
the month ending February 28, 2001, Group shall provide to the Lenders, as soon
as available but in any event not later than fifteen days after the end of each
calendar month, the unaudited statement of income of TruckersB2B.Com, Inc. for
such month, certified by a Responsible Officer as being fairly stated in all
material respects (subject to normal year-end audit adjustments), together with
a certificate of a Responsible Officer certifying as to Consolidated EBITDA of
TruckersB2B.Com, Inc. for such month and showing in detail the calculations
supporting such certification.

          5. Condition Precedent. This Amendment shall become effective on the
date (the "Amendment Effective Date") on which the following conditions
precedent shall have been satisfied:


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               (a) receipt by the Administrative Agent of this Amendment,
          executed and delivered by duly authorized officers of the Required
          Lenders and the Borrowers and acknowledged by each of the Guarantors;
          and

               (b) receipt by the Administrative Agent of this or any other
          documents relating hereto that shall be reasonably requested by the
          Administrative Agent.

          6.   No Default. On the Amendment Effective Date, (i) the Borrowers
shall be in compliance with all the terms and provisions set forth in the Loan
Documents on its part to be observed or performed, (ii) the representations and
warranties made and restated by the Borrowers pursuant to Section 7 of this
Amendment shall be true and complete on and as of such date with the same force
and effect as if made on and as of such date, and (iii) after giving effect to
the waivers set forth in Section 3 of this Amendment, no Default or Event of
Default shall have occurred and be continuing on such date.

          7.   Representations and Warranties. To induce the Administrative
Agent and the Lenders to enter into this Amendment, the Borrowers hereby
represent and warrant to the Administrative Agent and the Lenders that, after
giving effect to the amendments and waivers provided for herein, the
representations and warranties contained in the Credit Agreement and the other
Loan Documents will be true and correct in all material respects as if made on
and as of the date hereof and that no Default or Event of Default will have
occurred and be continuing.

          8.   Counterparts. This Amendment may be executed by one or more of
the parties hereto on any number of separate counterparts and all of said
counterparts taken together shall be deemed to constitute one and the same
instrument.

          9.   Expenses. Each Borrower, jointly and severally, hereby agrees to
pay and reimburse the Administrative Agent for all of the reasonable and
documented out-of-pocket costs and expenses incurred by the Administrative Agent
in connection with the preparation, execution and delivery of this Amendment,
including, without limitation, the fees and disbursements of Cadwalader,
Wickersham & Taft, counsel to the Administrative Agent.

          10.  Applicable Law. This Amendment shall be governed by, and
construed and interpreted in accordance with, the laws of the state of New York.

                            [SIGNATURE PAGES FOLLOW]


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          IN WITNESS WHEREOF, the parties hereto have caused this Amendment to
be duly executed and delivered as of the day and year first above written.


                                      CELADON GROUP, INC.



                                      By:      /s/ Roger T. Burbage
                                               --------------------
                                          Name:    Roger T. Burbage
                                          Title:   Secretary


                                      CELADON TRUCKING SERVICES, INC.



                                      By:      /s/ Roger T. Burbage
                                               --------------------
                                          Name:    Roger T. Burbage
                                          Title:   Secretary


                                      ING (U.S.) CAPITAL LLC, as Administrative
                                      Agent and as a Lender



                                      By:      /s/ William B. Redmond
                                               ----------------------
                                          Name:    William B. Redmond
                                          Title:   Vice President



<PAGE>   7

     The undersigned Lenders hereby consent and agree to the foregoing
Amendment:


                                      KEYBANK NATIONAL ASSOCIATION,
                                      as a Lender



                                      By:        /s/ Kevin Hipskind
                                                 ------------------
                                          Name:  Kevin Hipskind
                                          Title: Vice President


                                      NATIONAL BANK OF CANADA,
                                      as a Lender



                                      By:
                                          -----------------------
                                          Name:
                                          Title:


                                      UNION PLANTERS BANK, N.A.,
                                      as a Lender


                                      By:        /s/ David W. O'Neal
                                                 -------------------
                                          Name:  David W. O'Neal
                                          Title: Vice President


                                      THE NORTHERN TRUST COMPANY,
                                      as a Lender



                                      By:        /s/ Candelario Martinez
                                                 -----------------------
                                          Name:  Candelario Martinez
                                          Title: Vice President





<PAGE>   8
                                      FIFTH THIRD BANK, INDIANA, as a Lender



                                       By:       /s/ Geffrey L. Hale
                                                 -------------------
                                          Name:  Geffrey L. Hale
                                          Title: Vice President






<PAGE>   9
          The undersigned guarantors hereby consent and agree to the foregoing
Amendment:


                                      CELADON TRUCKING SERVICES OF INDIANA, INC.



                                      By:        /s/ Paul Will
                                                 -------------
                                          Name:  Paul Will
                                          Title: Secretary


                                      CELADON TRANSPORTATION, LLP



                                      By:        /s/ Paul Will
                                                 -------------
                                          Name:  Paul Will
                                          Title: Secretary


                                      CHEETAH BROKERAGE CO.



                                      By:        /s/ Paul Will
                                                 -------------
                                          Name:  Paul Will
                                          Title: Secretary


                                      CHEETAH TRANSPORTATION CO.



                                      By:        /s/ Paul Will
                                                 -------------
                                          Name:  Paul Will
                                          Title: Secretary



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                                      INTERNATIONAL FREIGHT HOLDING CORP.



                                      By:        /s/ Paul Will
                                                 -------------
                                          Name:  Paul Will
                                          Title:  Secretary

                                      JML FREIGHT FORWARDING, INC.



                                      By:        /s/ Paul Will
                                                 -------------
                                          Name:  Paul Will
                                          Title: Secretary


                                      RIL GROUP, LTD.



                                      By:        /s/ Paul Will
                                                 -------------
                                          Name:  Paul Will
                                          Title: Secretary


                                      RIL INC.



                                      By:        /s/ Paul Will
                                                 -------------
                                          Name:  Paul Will
                                          Title: Secretary


                                      WELLINGMUFT HOLDING CO.



                                      By:        /s/ Paul Will
                                                 -------------
                                          Name:  Paul Will
                                          Title: Secretary




<PAGE>   11

                                     CELADON LOGISTICS, INC.



                                     By:         /s/ Paul Will
                                                 -------------
                                         Name:   Paul Will
                                         Title:  Secretary


                                     RANDY EXPRESS, LTD.



                                     By:         /s/ Paul Will
                                                 -------------
                                         Name:   Paul Will
                                         Title:  Secretary


                                     RIL ACQUISITION CORP.



                                     By:         /s/ Paul Will
                                                 -------------
                                         Name:   Paul Will
                                         Title:  Secretary


                                     CELADON JACKY MAEDER CO.



                                     By:         /s/ Paul Will
                                                 -------------
                                         Name:   Paul Will
                                         Title:  Secretary


                                     ZIPP EXPRESS, INC.



                                     By:         /s/ Paul Will
                                                 -------------
                                         Name:   Paul Will
                                         Title:  Secretary



<PAGE>   12

                                       CELADON E-COMMERCE, INC.



                                       By:        /s/ Paul Will
                                                  -------------
                                           Name:  Paul Will
                                           Title: Secretary


                                       TRUCKERSB2B.COM, INC.



                                       By:        /s/ Paul Will
                                                  -------------
                                           Name:  Paul Will
                                           Title: Secretary