EXHIBIT D TO
                                                        STOCK PURCHASE AGREEMENT


                               SECURITIES PURCHASE
                                       AND
                             REGISTRATION AGREEMENT
                         (PIGGYBACK REGISTRATION RIGHTS)


     This  Agreement  is made and  entered as of April 19,  2000 by and  between
Knight Transportation, Inc., an Arizona corporation (the "Company"), and John R.
Fayard, Jr., a resident of Mississippi (the "Stockholder").

                                    RECITALS

     The Stockholder has agreed to sell to the Company the outstanding  stock of
John Fayard Fast Freight, Inc., a Mississippi corporation, pursuant to the Stock
Purchase  Agreement  dated  April  19,  2000  (the  "Purchase  Agreement").   In
consideration of Stockholder's sale of his stock to the Company, the Company has
agreed to deliver to Stockholder  certain shares of the Company's  common stock,
par value $0.01 per share and  additional  "earn-out"  shares of common stock to
the extent earned under the Purchase Agreement (the "Shares").

     The Company is a publicly  reporting  company  under  Section  12(g) of the
Securities  Exchange Act of 1934 (the  "Exchange  Act") and its shares of common
stock are traded on the NASDAQ National Market.

     The Stockholder is a sophisticated  person,  and he, his investment banker,
and tax counsel have had access to all publicly available information concerning
the Company.

     The Company  and the  Stockholder  wish to set forth the terms  pursuant to
which the  Stockholder  is accepting  the Shares and wish to provide for certain
registration  rights which accrue to the Stockholder  with respect to the Shares
and which the Company hereby grants the Stockholder.

                                    AGREEMENT

     NOW, THEREFORE, the parties agree, as follows:

     Section  1.  INFORMATION  PROVIDED  TO  STOCKHOLDER.  The  Stockholder  has
received from the Company  copies of (i) its most recent  reports filed with the
Securities  and  Exchange  Commission  ("SEC")  on Form  10-K and the  quarterly
reports filed by the Company with the SEC on Form 10-Q,  and the Company's  most
recent  Information  Statement.  The  Stockholder  has had an opportunity to ask
questions  and  receive  answers  concerning  the  Company,   its  organization,
business,  and  prospects.  The  Stockholder  is familiar with the Company,  its
business,  properties and financial condition. The Stockholder acknowledges that
information  concerning  the  Company is  available  publicly,  through the SEC,
through  various  Internet  sources  and  brokerage   houses.   The  Stockholder

represents  that he is an "accredited  investor" (as defined in Section 2(15) of
the  Securities Act of 1933 (the "Act") and Rule 501 of Regulation D promulgated
thereunder, and that he has had an opportunity to fully analyze and evaluate the
risks of proceeding with the transaction contemplated by the Purchase Agreement,
and  that he is  fully  capable  of  evaluating  the  risks  and  merits  of the
transaction  and has consulted  with his  professional  and  financial  advisors
regarding  the  transactions   contemplated  by  the  Purchase  Agreement.   The
Stockholder  and  his  advisors  have   substantial   experience  in  evaluating
businesses  such as the  Company.  The  Stockholder  agrees  that the Shares are
acquired  for  investment  only  and  will  not be sold or  distributed,  unless
registered  in  accordance  with  applicable  law or  unless an  exemption  from
registration is available,  in the opinion of counsel acceptable to the Company.
The Stockholder  understands  that a legend to that effect will be placed on the
Shares. The Stockholder  represents and warrants that in accepting the Shares as
consideration under the Purchase Agreement, he has relied solely upon the public
information   about  the  Company  and  that  the  Company  has  made  no  other
representations  or warranties  to him,  other than as set forth in the Purchase
Agreement. The Stockholder acknowledges that the Shares delivered by the Company
have not been registered with the SEC, and that the Company's only obligation to
register such shares is set forth in this Agreement.

     Section 2. REGISTRATION UNDER THE ACT.

     (a) If the Company  files a  registration  statement  under the Act,  which
relates to a current offering of securities of the class then represented by the
Shares  (except  in  connection  with any  acquisition,  or an  offering  of the
Company's equity securities to its employees pursuant to any employee benefit or
any stock  option plan,  or any dividend  reinvestment  plan  maintained  by the
Company), such registration statement and the prospectus included therein shall,
at the written request of the Stockholder,  include,  subject to any underwriter
requirements  or cutbacks,  all or part of the Shares  owned by the  Stockholder
under the  registration  statement so as to permit the public sale of the Shares
by the  Stockholder  in compliance  with the Act. The Company shall give written
notice to the  Stockholder  of its  intention to file a  registration  statement
under the Act  relating to an offering  of its equity  securities  not less than
thirty (30) days prior to the filing of such registration statement with the SEC
or any  successor  in interest  (or such  shorter  period if 30-days'  notice is
impracticable).  The Stockholder's  written request to the Company that all or a
portion of his Shares be included  in the  registration  statement,  if made not
later than  twenty  (20) days prior to the date  specified  in the notice as the
date on which the Company intends to file its registration statement (or, in any
event, within five (5) days after receiving notice), shall allow the Stockholder
to register all or part of his Shares under such registration statement. Neither
the  Company's  delivery of notice nor delivery of a request by the  Stockholder
for registration shall in any way obligate the Company to file such registration
statement and,  notwithstanding the filing of such registration  statement,  the
Company may, at any time prior to the effective  date thereof,  determine not to
offer the  securities  to which such  registration  statement  relates,  without
liability  to the  Stockholder.  The  Company  shall pay the entire  cost of any
registration  of Shares to which this Section 2(a)  applies,  including  without
limitation,  attorneys' fees,  accounting fees,  filing fees and printing costs,
but  excluding  any  underwriter's   discount;   provided,   however,  that  the
Stockholder  shall be solely  responsible for any  underwriter  discounts on any
Shares sold by the Stockholder  pursuant to any registration  statement filed by
the Company.  A Stockholder  who  exercises  his rights under this  Agreement is
sometimes referred to herein as a "Selling Stockholder."

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     (b) If any Shares  registered  under this Agreement are offered  through an
underwriter,  each Selling Stockholder and the Company agrees (i) to execute any
underwriting agreement requested by the underwriter,  (ii) furnish any indemnity
in the customary form required by the underwriter, (iii) furnish any information
required by the underwriter, and (iv) take any other action reasonably necessary
to satisfy the underwriting conditions or to cause the registration statement to
become  effective.  The rights of any Selling  Stockholder  under this Agreement
shall be subject to and  limited by the terms and  conditions  of any  indemnity
agreement and any other conditions the underwriter may impose.  The failure of a
Selling  Stockholder  to comply with the  provision  of this  Section 2(b) shall
relieve the Company of the obligation to register the Shares as provided by this
Agreement.

     Section 3.  COMPLIANCE  WITH LAW. Any  registration  statement filed by the
Company  pursuant to the Act shall comply in all  respects  with the Act and all
rules and regulations of the SEC applicable to such registration  statement.  At
such time as any  registration  statement  (or notice)  becomes  effective,  the
Company shall supply to the Selling Stockholder and to any person or underwriter
acting on his behalf,  sufficient  copies of the  prospectus  used in connection
with the registration statement for the Selling Stockholder to sell publicly the
registered  Shares.  With respect to any  registration of Shares subject to this
Agreement, the Company, at its expense, agrees to qualify or register the Shares
in any  state in which  the  Selling  Stockholder  requests  that the  Shares be
qualified or registered, to the extent that the Company is reasonably able to do
so, and the Company shall maintain such  qualification or registration in effect
for so long as the registration statement is in effect.

     Section  4.  SELLING   STOCKHOLDER'S  CONSENT  AND  OBLIGATION  TO  FURNISH
INFORMATION.  The Selling Stockholder shall promptly provide to the Company such
consents and  information as may be reasonably  required by the Company in order
to perform  its  obligations  under  Section 2 hereof.  It shall be a  condition
precedent  to the  obligations  of the  Company to take any action  pursuant  to
Section 2(a), 2(b), 7(a), or 7(b) that the Selling  Stockholder shall furnish to
the Company such  information  regarding the Selling  Stockholder and the Shares
held by him, and the intended  method of disposition of such securities as shall
be required to effect the registration of the Shares.

     Section 5. "MARKET  STAND-OFF"  AGREEMENT.  The Selling  Stockholder agrees
that he will not, to the extent  requested  by the Company and any  underwriter,
sell or  otherwise  transfer or dispose of any Shares  (other than Shares  being
registered  in such  offering)  for up to that  period  of  time  following  the
effective date of a registration statement of the Company filed under the Act as
is requested by the managing underwriter(s) of such offering. The Company agrees
that any lock-up  agreement  obtained  by the  underwriter  with  respect to the
Selling  Stockholder will be no longer than any similar agreement  applicable to
the  Company or its  affiliates  in  connection  with any shares of the  Company
registered by the Company pursuant to such registration  statement.  The Selling
Stockholder  agrees to execute any lock-up  agreement  required by the  managing
underwriter.

     Section 6. REPORTS.  In connection with any registration of its Shares, the
Company at all times will  comply  with the Act and will file such  reports  and
disclosures  as may  be  required  by  the  Act  or  any  rules  or  regulations
promulgated  thereunder.  If the  Company is subject to the  Exchange  Act,  the

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Company  agrees to file timely all reports  required by the Exchange Act. If the
Company is a listed company on NASDAQ or any national securities  exchange,  the
Company shall file all reports necessary to maintain such listing.

     Section 7. INDEMNIFICATION.

     (a) COMPANY.  The Company agrees to indemnify and hold harmless the Selling
Stockholder and any underwriter,  to the extent applicable,  and any person who,
within  the  meaning  of the Act (or the  Exchange  Act),  controls  any of such
persons  (hereafter,  individually and  collectively,  the "Selling Group") for,
from,  and  against any  losses,  claims,  damages,  or  liabilities,  joint and
several,  to which the Selling  Group,  or any of them, may become subject under
the Act,  the  Exchange  Act,  or  otherwise,  insofar as such  losses,  claims,
damages,  or  liabilities  (or actions in respect  thereof)  arise out of or are
based upon any untrue statement or alleged untrue statement of any material fact
contained  in a  registration  statement,  or  the  prospectus  which  is a part
thereof,  or any amendment or supplement  thereto,  or arise out of or are based
upon the omission or alleged omission to state therein a material fact necessary
to be stated therein to make the  statements  therein not  misleading;  and will
reimburse the Selling Group and each of them for any legal or other expenses and
costs  reasonably  incurred  by them in  connection  with the  investigation  or
defense  of any such  loss,  claim,  damage,  liability,  or  action;  provided,
however, that the Company will not be liable under this Section 7(a) if any such
loss, claim,  damage, or liability arises solely out of or is based solely on an
untrue  statement or alleged  untrue  statement or omission or alleged  omission
made  in the  registration  statement  or the  prospectus  or any  amendment  or
supplement  thereto in reliance upon and in conformity with written  information
furnished to the Company by or on behalf of the Selling  Group or any of them. A
member of the Selling Group who is treated as a control  person under the Act or
the Exchange Act shall be covered by and included within the indemnity  provided
by this Section 7(a) for all losses,  claims,  damages, and liabilities asserted
in connection with the registration statement, notice or the sale of the Shares,
whether or not based on Section 15 of the Act or Section 20 of the Exchange Act.
The  indemnity  obligation  provided  herein is in addition to any  liability or
obligation  which the Company may otherwise  have to the Selling Group or any of
them or which may exist at common law or under any applicable statute.

     (b) SELLING  GROUP.  Each member of the Selling Group,  severally,  but not
jointly,  will  indemnify and hold harmless the Company,  each of its directors,
each of its officers who signs the  registration  statement,  and any person who
controls the Company  within the meaning of the Act (or the  Exchange  Act) for,
from,  and against any losses,  claims,  damages,  or  liabilities  to which the
Company or any such director or officer or controlling person may become subject
under the Act, the Exchange Act, or otherwise,  if such losses, claims, damages,
or liabilities (or actions in respect  thereof) arise solely out of or are based
solely on any untrue or alleged untrue statement of a material fact contained in
the  registration  statement,  the  prospectus,  or any  amendment or supplement
thereto,  or arise out of or are based upon the omission or alleged  omission to
state  therein  a  material  fact  necessary  to be stated  therein  to make the
statements  therein  not  misleading,  in each case if, and only if, such untrue
statement or alleged untrue  statement or omission or alleged  omission was made
in the registration statement,  the prospectus,  or such amendment or supplement
in reliance  upon and in conformity  with written  information  concerning  such
member of the  Selling  Group  furnished  to the Company by or on behalf of such
member  of the  Selling  Group  for use in the  registration  statement  and the

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prospectus or any amendment or supplement thereto,  and will reimburse any legal
or other expense reasonably  incurred by the Company or such director or officer
or controlling  person in connection  with  investigating  or defending any such
loss, claim,  damage,  liability,  or action. This indemnity obligation provided
hereunder is in addition to any other liability or obligation  which the Selling
Group or each member of the Selling Group  separately  may otherwise have to the
Company or which may exist at common law or under any applicable statute.

     (c)  CLAIMS.  Promptly  after  receipt by an  indemnified  party under this
Section 7(c) of notice of the  commencement  of any action or the  initiation of
any proceeding  (including,  without limitation,  arbitration),  the indemnified
party will, if a claim in respect thereof is to be made against any indemnifying
party under this Section 7(c),  notify the indemnifying  party in writing of the
commencement  thereof; but the failure to notify the indemnifying party will not
relieve  it from  any  liability  which  it may  have to any  indemnified  party
otherwise than under this Section 7(c),  unless failure to notify  prejudices or
causes  material  harm to the  indemnifying  party.  In case any such  action is
brought against any indemnified  party and such  indemnified  party notifies any
indemnifying party of the commencement  thereof, the indemnifying party shall be
entitled to  participate  therein  and, to the extent that it may wish,  jointly
with any other indemnifying party similarly notified, assume the defense thereof
with counsel who shall be reasonably satisfactory to such indemnified party and,
after  notice  from  the  indemnifying  party to such  indemnified  party of its
election to so assume the defense thereof,  the  indemnifying  party will not be
liable to such indemnified  party under this Section 7(c) for any legal or other
expenses  subsequently incurred by such indemnified party in connection with the
defense  thereof  other  than  reasonable  costs of  investigation.  In any such
action,  any  indemnified  party shall have the right to retain his own counsel,
but the fees and  expenses  of such  counsel  shall  be at the  expense  of such
indemnified  party unless (i) the indemnifying  party and the indemnified  party
shall have mutually  agreed to the retention of such counsel,  or (ii) the named
parties to any such proceeding  (including any impleaded  parties)  include both
the  indemnifying  party and the indemnified  party and  representation  of both
parties by the same counsel  would be  inappropriate  due to actual or potential
differing or conflicting  interests  between them. The indemnifying  party shall
not be liable for any settlement of any proceeding or claim effected without its
written  consent,  but if  settled  with  such  consent  or if  there is a final
judgment for the  plaintiff,  the  indemnifying  party  agrees to indemnify  the
indemnified  party for, from and against any loss or liability by reason of such
settlement  or judgment.  The  indemnified  party shall  cooperate  fully in the
defense of any claim subject to  indemnification  hereunder  and shall,  without
limiting  this  duty  of  cooperation,   make  himself  available  for  pretrial
investigation and preparation,  depositions,  and interviews by the indemnifying
party's legal counsel.

     (d) ENFORCEABILITY. If the indemnification provided in Sections 7(a), 7(b),
and 7(c) is, for any reason, other than as specified in such subparagraphs, held
by a court to be  unavailable  and the Company (or its  directors,  officers who
sign the registration statement,  and any person who controls the Company within
the  meaning of the Act or  Exchange  Act),  the  Selling  Group,  or any member
thereof has been  required to pay  damages as a result of a  determination  by a
court that the preliminary prospectus,  registration statement,  the prospectus,
or any  amendment  or  supplement  thereto  contains  an untrue  statement  of a
material fact or omits to state a material fact  necessary to be stated  therein
to make the statements therein not misleading, then the Company shall contribute
to the damages paid by the Selling Group or any member thereof,  and the Selling
Group shall  contribute  to the damages  paid by the Company (or its  directors,
officers who sign the  registration  statement,  and any person who controls the

                                       5

Company within the meaning of the Act or Exchange Act), but in each case only to
the  extent  that  such  damages  arise out of or are  based  upon  such  untrue
statement or  omission,  in such  proportion  as is  appropriate  to reflect the
relative  fault  of the  Company  (or  its  directors,  officers  who  sign  the
registration  statement,  and any person who  controls  the  Company  within the
meaning of the Act or Exchange Act), the Selling Group, or any member thereof in
connection with the statements or omissions  which resulted in such damages,  as
well as any other relevant equitable considerations. The relative fault shall be
determined by reference to, among other things,  whether the untrue statement of
a material fact or the omission to state a material fact relates to  information
supplied by the  Company,  the Selling  Group,  or any member  thereof,  and the
parties' relative intent, knowledge,  access to information,  and opportunity to
correct or prevent  such untrue  statement  or  omission.  For  purposes of this
Section 7(d),  the term  "damages"  shall  include any legal and other  expenses
reasonably  incurred  by the Company (or its  directors,  officers  who sign the
registration  statement,  and any person who  controls  the  Company  within the
meaning of the Act or Exchange Act), the Selling Group, or any member thereof in
connection  with  investigating  and  defending any action or claim which is the
subject of the contribution  provisions of this Section 7(d). No person adjudged
guilty of fraudulent  misrepresentation  within the meaning of Section 11 of the
Act shall be  entitled  to  contribution  from any person  who was not  adjudged
guilty of such fraudulent misrepresentation.

     (e) TERM.  The  agreements  contained  in Sections  7(a)  through (d) shall
remain   operative  and  in  full  force  and  effect   regardless  of  (i)  any
investigation made by or on behalf of the Selling Group or any of them, or by or
on behalf of the  Company,  any of its  directors  or  officers,  or any  person
controlling the Company, and (ii) any termination of this Agreement. A successor
of the Selling  Group,  or any of them,  or of the  Company,  or any director or
officer  thereof,  or any person  controlling  the Selling  Group or the Company
shall be entitled to the benefits of the  agreements  contained in Sections 7(a)
through (e) herein.

     Section 8. NOTICE.  Any notices required or permitted to be given hereunder
shall be in writing and may be served personally or by mail; and if served shall
be addressed as follows:

     If to the Company:

                  Knight Transportation, Inc.
                  Attn: Kevin P. Knight
                  Chief Executive Officer
                  5601 West Buckeye Road
                  Phoenix, Arizona 85043
                  Telephone: (602) 269-2000
                  Facsimile: (602) 269-8409

         With a copy to:

                  Mark A. Scudder
                  Scudder Law Firm, P.C.
                  411 S. 13th Street, Suite 200
                  Lincoln, Nebraska 68508
                  Telephone: (402) 435-3223
                  Facsimile: (402) 435-4239

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         If to the Stockholder:

                  John R. Fayard, Jr.
                  P. O. Box 2939
                  Gulfport, Mississippi  39503
                  Telephone: ________________
                  Facsimile: _________________

         With a copy to:

                  Frederick T. Hoff
                  Newton and Hoff, L.L.P.
                  2019 23rd Avenue
                  Gulfport, Mississippi 39502
                  Telephone:        (228) 863-8827
                  Facsimile:        (228) 868-6007

     Any notice (or response to notice)  given by mail shall be deemed given and
received if personally delivered by commercial courier or mail at the address as
specified above. Notice given personally shall be deemed given and received upon
delivery to the party to whom such notice is addressed. Any party may by written
notice to the other specify a different address for notice purposes.

     Section  9.  BINDING  AGREEMENT,  ASSIGNABILITY.  This  Agreement  shall be
binding upon each of the parties hereto and the heirs,  successors,  and assigns
of  each.  The  registration  rights  hereunder  are  assignable,  but  only  in
connection   with  the  sale  or   transfer  of  the   Shares.   The   foregoing
notwithstanding,  any pledgee (and any assignee or successor of such pledgee) of
all or part of the  Shares  shall  have the same  rights  to  require  or obtain
registration  of the Shares as the  Stockholder  who is the record owner of such
pledged  Shares,  and the pledgee of such  Shares  shall be deemed to be a third
party  beneficiary  of the  Agreement  who is  entitled to enforce the terms and
conditions  hereof to the same extent as if such pledgee were the Stockholder of
the Shares so pledged.

     Section 10. ATTORNEYS' FEES. In the event any legal action or proceeding of
any nature (including arbitration) is brought by any party hereto to enforce its
rights hereunder,  the prevailing party shall be entitled to attorneys' fees and
all costs and expenses,  whether or not such costs and expenses are taxable. The
parties  agree that  failure to register  the Shares as required  hereunder  may
cause  irreparable  harm to the party  seeking  registration;  accordingly,  the
parties  agree that the  remedy of  specific  performance  is  available  to any
nonbreaching party hereunder.

     Section 11. RECITALS. The recitals shall constitute part of this Agreement.

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     Section 12.  DURATION.  Seller's  registration  rights under this Agreement
shall  terminate  on the  earlier  of (i) the date all  Shares  subject  to this
Agreement have been  registered  with the SEC, or (ii) the third  anniversary of
the date of this Agreement.

     Section  13.  GOVERNING  LAW.  This  Agreement  shall  be  governed  by and
construed under the laws of the State of Arizona.

     EXECUTED as of the date first above written.

STOCKHOLDER:                      KNIGHT TRANSPORTATION, INC.,
                                  AN ARIZONA CORPORATION


/s/ John R. Fayard, Jr.           By: /s/ Clark A. Jenkins
- ------------------------------        ------------------------------------------
John R. Fayard, Jr.                   Clark A. Jenkins, Executive Vice President

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