Exhibit 4.2


                                AMENDMENT TO THE
               ARKANSAS BEST CORPORATION SUPPLEMENTAL BENEFIT PLAN


         Amendment made effective April 19, 2000, by Arkansas Best  Corporation,
a Delaware corporation, (the "Company").

                              W I T N E S S E T H:

         WHEREAS,  Arkansas  Best  Corporation  established  the  Arkansas  Best
Corporation  Supplemental Benefit Plan (the "Plan"),  effective January 1, 1988;
and

         WHEREAS, effective April 19, 2000, the Company now desires to amend the
Plan to expand and to clarify the definition of "Change in Control"; and

         WHEREAS,  the  Plan  may be  amended  by the  Company  pursuant  to the
provisions  of Section  8.4 of the Plan,  and the  Company  desires to amend the
Plan.

         NOW, THEREFORE, the Plan is amended as follows,  effective as set forth
above:

         1.  Existing  Section  2.1(j)  is  deleted  in its  entirety,  and  the
following is substituted in its place:

         "(j)     "Change in Control"  shall mean the earliest date on which any
                  of the following events shall occur:

                  (i)      there  shall  be  consummated  any  consolidation  or
                           merger of the Company in which the Company is not the
                           continuing  or surviving  corporation  or pursuant to
                           which the  Company's  common stock would be converted
                           into  cash,  securities,  or other  property,  or any
                           lease, exchange or other transfer (excluding transfer
                           by  way  of   pledge   or   hypothecation),   in  one
                           transaction or a series of related  transactions,  of
                           all,  or  substantially  all,  of the  assets  of the
                           Company,  other than any such consolidation,  merger,
                           lease,  exchange or transfer in which the Company, or
                           any  of  its  affiliates,   or  the  holders  of  the
                           Company's common stock  immediately prior to any such
                           actions  have at  least  a  fifty-one  percent  (51%)
                           ownership  of the  surviving  corporation  after  the
                           consolidation  or merger of the  entity to which such
                           assets  are   transferred,   leased,   exchanged   or
                           otherwise transferred.

                  (ii)     the  shareholders  of the Company approve any plan or
                           proposal for the  liquidation  or  dissolution of the
                           Company.



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                  (iii)    any "person"  (as such is defined in Section  3(a)(9)
                           or Section 13(d)(3) under the Securities Exchange Act
                           of 1934 [the  "1934  Act"]) or any  "group"  (as such
                           term is used in Rule 13d-5 promulgated under the 1934
                           Act) other than the Company or any  successor  of the
                           Company  or  any  subsidiary  of the  Company  or any
                           employee   benefit   plan  of  the   Company  or  any
                           subsidiary (including such plan's trustee), becomes a
                           beneficial   owner  for   purposes   of  Rule   13d-3
                           promulgated   under   the  1934  Act,   directly   or
                           indirectly,  of securities of the Company represented
                           thirty-five  percent  (35%) or more of the  Company's
                           then outstanding  securities having the right to vote
                           in the election of directors.

                  (iv)     if at any time the Continuing  Directors then serving
                           on the Board of  Directors  cease  for any  reason to
                           constitute at least a majority thereof.

                           "Continuing  Director"  shall mean a Director  of the
                           Company  who either (A) is a Director  of the Company
                           on the date hereof, or (B) whose initial  appointment
                           or initial nomination for election or election by the
                           Company's  shareholders was approved by a majority of
                           the  Continuing  Directors  (including any successors
                           elected pursuant to this Subsection (iv)) then on the
                           Company Board of Directors.

                  (v)      any person or group (as defined in  Subsection  (iii)
                           above) commences a tender offer or exchange offer for
                           all or less  than all of the  share of the  Company's
                           issued and outstanding common stock that would result
                           in, upon the  consummation of such offer,  the person
                           or  group,   together   with  all  of  its  or  their
                           affiliates,  beneficially  owning  25% or more of the
                           Company's  common  stock,  and which  offer  does not
                           include a binding  written  commitment by the offeror
                           to  purchase  any  shares  that are not  tendered  or
                           exchanged for the same cash  consideration (or in the
                           event of any exchange  offer,  the cash equivalent of
                           the  fair  market  value of the  securities  or their
                           property  offered in the  exchange,  as determined by
                           the   Company's   Board  of  Directors  in  its  sole
                           discretion) within 90 days following the consummation
                           of the tender or exchange offer;  provided,  however,
                           that if the tender offer or exchange offer that would
                           have  otherwise  resulted  in a Change in  Control is
                           canceled,   terminated  withdrawn  or  otherwise  not
                           consummated, such offer shall be deemed never to have
                           been made and no Change in Control shall be deemed to
                           have occurred."


         IN WITNESS WHEREOF,  Arkansas Best  Corporation,  acting by and through
its duly authorized officer,  has executed this document on this the 25th day of
May, 2000.

                                            ARKANSAS BEST CORPORATION


                                            By:  /s/ Richard F. Cooper
                                               --------------------------------
                                               Its:  Vice President -
                                                     Administration