Exhibit 10.6  WAIVER, FIFTH AMENDMENT TO AMENDED AND RESTATED CREDIT AGREEMENT AND REAFFIRMATION OF GUARANTIES  THIS
WAIVER, FIFTH AMENDMENT TO AMENDED AND RESTATED CREDIT AGREEMENT AND
REAFFIRMATION OF GUARANTIES, dated as of February 9, 2009 (this Fifth Amendment), is entered into by and between Quixote
Corporation, a Delaware corporation (the Borrower),
whose address is 35 East Wacker Drive, Chicago, Illinois 60601, and Quixote
Transportation Safety, Inc., Transafe Corporation, Energy Absorption Systems, Inc.,
Energy Absorption Systems (AL) LLC, Surface Systems, Inc., Nu-Metrics, Inc.,
and Highway Information Systems, Inc., as Subsidiary Guarantors, (each
being referred to herein as a Guarantor and
collectively referred to herein as the Guarantors),
and Bank of America, N.A., as successor by merger to LaSalle Bank National
Association, a national banking association (the Lender),
whose address is 135 South LaSalle Street, Chicago, Illinois 60603.  R E C I TAL S:  A.            Borrower and Lender entered into
that certain Amended and Restated Credit Agreement, dated as of April 20,
2005 (the Original Credit Agreement), as
amended by that certain First Amendment to Amended and Restated Credit
Agreement and Reaffirmation of Guaranties dated as of December 1, 2006,
(the First Amendment), that certain Second
Amendment to Amended and Restated Credit Agreement and Reaffirmation of
Guaranties dated as of March 15, 2007 (the Second
Amendment), that certain Third Amendment to Amended and Restated
Credit Agreement and Reaffirmation of Guaranties dated as of November 7,
2007 (the Third Amendment) and that certain
Fourth Amendment to Amended and Restated Credit Agreement and Reaffirmation of
Guaranties dated as of November 7, 2008 (the Fourth
Amendment, and together with the Original Credit Agreement, the
First Amendment, the Second Amendment and the Third Amendment, the Credit Agreement) pursuant to which Credit Agreement Lender
has made a Revolving Loan to Borrower evidenced by that certain Amended and
Restated Revolving Loan Note, dated as of November 7, 2007, in the maximum
principal amount of $40,000,000, executed by Borrower and made payable to the
order of Lender (the Revolving Note).  B.            In connection with the Original
Credit Agreement, the Guarantors executed and delivered to Lender that certain
Guaranty dated as of May 16, 2003 in favor of Lender, as amended by that
Reaffirmation and Amendment of Subsidiary Guaranty dated as of April 20,
2005 (the Guaranty).  C.            Borrower has failed to comply with Section 7.4(D) and
7.4(E) of the Credit Agreement for the period ending December 31,
2008 (the Existing Defaults).  Borrower has requested that Bank waive the
Existing Defaults and Bank has agreed to waive the Existing Defaults on the
terms and conditions set forth herein.  D.            Borrower and the Guarantors have
also requested, and Lender has agreed to, the modification of certain terms
contained in the Credit Agreement as set forth herein, all pursuant to the
terms and conditions hereinafter set forth herein.  NOW
THEREFORE, in consideration of the premises and other good and valuable
consideration, the receipt and adequacy of which are hereby acknowledged,
Borrower, the Guarantors and Lender hereby agree as follows:


A G R E E MEN T S:  1.             RECITALS.  The foregoing Recitals are hereby made a part
of this Fifth Amendment.  2.             DEFINITIONS.  Capitalized words and phrases used herein
without definition shall have the respective meanings ascribed thereto in the
Credit Agreement.  3.             WAIVER.  Subject to the terms hereof, Lender, hereby
waives the Existing Defaults.  Lender and
Borrower hereby agree that the foregoing waiver of the Existing Defaults shall
in no way be deemed to be a waiver or forbearance of any other default, any
Unmatured Default or any other Event of Default, whether now existing or
hereafter arising, under the Credit Agreement (whether occurring before or
after giving effect to this Fifth Amendment) or any other Loan Document.  4.             AMENDMENTS TO
THE CREDIT AGREEMENT.  4.1           Section 1.1
of the Credit Agreement.  (a)           The
definition of Revolving Loan Commitment in Section 1.1 of the Credit
Agreement is hereby deleted in its entirety and restated as follows:  Revolving Loan Commitment means the obligation of
Lender to make Revolving Loans and to issue Letters of Credit in an aggregate
amount not exceeding Fifteen Million and 00/100 Dollars ($15,000,000) as such
amount may be modified from time to time pursuant to these the terms of this
Agreement.  (b)           The
definition of Revolving Loan Termination Date: is hereby deleted in its
entirety and replaced with the following:  Revolving Loan Termination Date means November 1, 2009.  4.2           Section 2.13
of the Credit Agreement.  Section 2.13(D)(ii) is
hereby amended by deleting the existing pricing grid in its entirety and
replacing it with the following:  Level
  
  Maximum
  Total Leverage
  Ratio
  
  Applicable
  Eurodollar
  Margin/L/C Fee
  Percentage
  
  Applicable ABR
  Margin
  
  Commitment
  Fee
  PercentageV
  
  >5.00
  
  3.75
  %
  3.75
  %
  0.75
  %IV
  
  >4.00 BUT <5.00
  
  3.25
  %
  3.25
  %
  0.75
  %III
  
  >3.00 BUT <4.00
  
  2.75
  %
  2.75
  %
  0.50
  %II
  
  >2.00 BUT <3.00
  
  2.25
  %
  2.25
  %
  0.50
  %I
  
  <2.00
  
  1.75
  %
  1.75
  %
  0.375
  %  4.3           Section 7.3(F) of
the Credit Agreement.  Section 7.3(F) of
the Credit Agreement is hereby deleted in its entirety and restated as follows:  (F)Restricted Payments.  The Borrower shall not declare or make any
Restricted Payments without the prior written consent of the Lender.  4.4           Revolving
Note.  All references in the Credit
Agreement to the Revolving Note  2


in the form of Exhibit G to the Credit Agreement shall be deemed
to be references to the Second Amended and Restated Revolving Note in the form
of Exhibit A attached hereto and made a part hereof (the Second Amended Note).  5.             REAFFIRMATION OF
GUARANTIES.  Each of the Guarantors
hereby expressly (a) consents to the execution by Borrower and Lender of
this Fifth Amendment, (b) acknowledges that the Guaranteed Debt (as
defined in each of the Guaranties) includes all of the obligations and
liabilities owing from Borrower to Lender, including, but not limited to, the
obligations and liabilities of Borrower to Lender under and pursuant to the
Credit Agreement, as amended from time to time, and as evidenced by the Revolving
Note, as modified, extended and/or replaced from time to time, (c) reaffirms,
assumes and binds themselves in all respects to all of the obligations,
liabilities, duties, covenants, terms and conditions that are contained in
their respective Guaranty, (d) agrees that all such obligations and
liabilities under their respective Guaranty shall continue in full force and
effect and shall not be discharged, limited, impaired or affected in any manner
whatsoever, and (e) represents and warrants that each of the
representations and warranties made by such Guarantor in any of the documents
executed in connection with the Loans remain true and correct as of the date
hereof.  6.             REPRESENTATIONS
AND WARRANTIES.  To induce Lender to
enter into this Fifth Amendment, Borrower and each Guarantor hereby certifies,
represents and warrants to Lender that:  6.1           Organization.  Borrower and each Guarantor is a corporation
or a limited liability company duly organized, existing and in good standing
under the laws of its state or organization with full and adequate corporate or
limited liability power, as the case may be, to carry on and conduct its
business as presently conducted. 
Borrower and each Guarantor is duly licensed or qualified in all foreign
jurisdictions wherein the nature of its activities require such qualification
or licensing.  The Articles of
Incorporation or Organization, as the case may be, Bylaws (other than an
amendment to the By-laws of Borrower dated July 24, 2008) or Operating
Agreement, as the case may be, Resolutions and Incumbency Certificate of
Borrower and each Guarantor have not been changed or amended since the
certified copies thereof were delivered to Lender in connection with the
Original Credit Agreement and the First Amendment.  The state issued organizational
identification number for Borrower and each Guarantor is listed on Schedule
I hereto.  The exact legal name of
Borrower and each Guarantor is as set forth in the preamble of this Fifth
Amendment, and neither Borrower nor any Guarantor currently conducts, nor has
it during the last five (5) years conducted, business under any other name
or trade name.  Neither Borrower nor any
Guarantor will change its name, its organizational identification number, if it
has one, its type of organization, its jurisdiction of organization or other
legal structure.  6.2           Authorization.  Borrower and each Guarantor is duly
authorized to execute and deliver this Fifth Amendment and Borrower is and will
continue to be duly authorized to borrow monies under the Credit Agreement, as
amended hereby, and to perform its obligations under the Credit Agreement, as
amended hereby.  6.3           No
Conflicts.  The execution and
delivery of this Fifth Amendment and the performance by Borrower and each
Guarantor of its obligations under the Credit Agreement, as amended hereby, do
not and will not conflict with any provision of law or of the articles of
incorporation or bylaws of Borrower or any Guarantor or of any agreement
binding upon Borrower or any Guarantor.  6.4           Validity
and Binding Effect.  The Credit
Agreement, as amended hereby, is a legal, valid and binding obligation of
Borrower and each Guarantor, enforceable against Borrower and each Guarantor in
accordance with its terms, except as enforceability may be  3


limited by bankruptcy, insolvency or other similar laws of general
application affecting the enforcement of creditors rights or by general
principles of equity limiting the availability of equitable remedies.  6.5           Compliance
with Credit Agreement.  The
representation and warranties set forth in Section VI of the Credit
Agreement, as amended hereby, are true and correct with the same effect as if
such representations and warranties had been made on the date hereof, with the
exception that all references to the financial statements shall mean the
financial statements most recently delivered to Lender and except for such
changes as are specifically permitted under the Credit Agreement.  In addition, other than as waived in Section 2
hereof, Borrower and each Guarantor has complied with and is in compliance with
all of the covenants set forth in the Credit Agreement, as amended hereby,
including, but not limited to, those set forth in Section VII thereof.  6.6           No
Event of Default.  As of the date
hereof, no Event of Default under Section VII of the Credit Agreement, as
amended hereby, or event or condition which, with the giving of notice or the
passage of time, or both, would constitute an Event of Default, has occurred or
is continuing.  6.7           No
Subordinated Debt Default.  As of the
date hereof, no default under any of the documents evidencing or securing any
of the Subordinated Debt, or event or condition which, with the giving of
notice or the passage of time, or both, would constitute a default under any of
the documents evidencing or securing any of the Subordinated Debt, has occurred
or is continuing.  6.8           Schedules
to Credit Agreement.  Other than as
shown by the updated Schedules attached hereto as Exhibit A, the
Schedules attached to the Credit Agreement are true and correct as of the date
hereof.  7.             CONDITIONS
PRECEDENT.  This Fifth Amendment
shall become effective as of the date above first written after receipt by
Lender of the following:  7.1           Fifth
Amendment.  This Fifth Amendment
executed by Borrower, the Guarantors, and Lender.  7.2           Second
Amended Note.  The Second Amended
Note executed by Borrower.  7.3           Resolutions.  A certified copy of Resolutions of the board
of directors of Borrower and each Guarantor authorizing the execution, delivery
and performance of this Fifth Amendment and related loan documents.  7.4           Certificate
of Good Standing.  Certificates of
Good Standing for Borrower and each Guarantor from their respective
jurisdictions of organization.  7.5           Amendment
Fee.  An amendment fee in the amount
of $37,500.  7.6           Other
Documents.  Such other documents,
certificates and/or opinions of counsel as Lender may request.  4


8.             GENERAL.  8.1           Governing
Law; Severability.  This Fifth
Amendment shall be construed in accordance with and governed by the laws of
Illinois.  Wherever possible each
provision of the Credit Agreement and this Fifth Amendment shall be interpreted
in such manner as to be effective and valid under applicable law, but if any
provision of the Credit Agreement and this Fifth Amendment shall be prohibited
by or invalid under such law, such provision shall be ineffective to the extent
of such prohibition or invalidity, without invalidating the remainder of such
provision or the remaining provisions of the Credit Agreement and this Fifth
Amendment.  8.2           Successors
and Assigns.  This Fifth Amendment
shall be binding upon Borrower, the Guarantors, and Lender and their respective
successors and assigns, and shall inure to the benefit of Borrower, the
Guarantors, and Lender and the successors and assigns of Lender.  8.3           Waiver
of Claims.  Borrower hereby
acknowledges, agrees and affirms that it possesses no claims, defenses,
offsets, recoupment or counterclaims of any kind or nature against or with
respect to the enforcement of the Credit Agreement, as amended hereby, the
Revolving Note or any other Loan Document (collectively referred to herein as
the Claims), nor does Borrower now have
knowledge of any facts that would or might give rise to any Claims.  If facts now exist which would or could give
rise to any Claim against or with respect to the enforcement of the Credit
Agreement as amended hereby, the Revolving Note, and/or any other Loan
Documents, Borrower hereby unconditionally, irrevocably and unequivocally
waives and fully releases any and all such Claims as if such Claims were the
subject of a lawsuit, adjudicated to final judgment from which no appeal could
be taken and therein dismissed with prejudice.  8.4           Continuing
Force and Effect of Loan Documents and Guaranty.  Except as specifically modified or amended by
the terms of this Fifth Amendment, all other terms and provisions of the Credit
Agreement and the other Loan Documents are incorporated by reference herein,
and in all respects, shall continue in full force and effect.  Borrower, by execution of this Fifth
Amendment, hereby reaffirms, assumes and binds itself to all of the
obligations, duties, rights, covenants, terms and conditions that are contained
in the Credit Agreement and the other Loan Documents.  Each of the Guarantors, by execution of this
Fifth Amendment, hereby reaffirms, assumes and binds itself to all of the
obligations, duties, rights, covenants, terms and conditions that are contained
in Guaranty.  8.5           Financing
Statements.  Borrower hereby
irrevocably authorizes Lender at any time and from time to time to file in any
jurisdiction any initial UCC financing statements and/or amendments thereto
that (a) describe the Collateral, and (b) contain any other
information required by part 5 of Article 9 of the UCC for the sufficiency
or filing office acceptance of any financing statement or amendment.  8.6           References
to Credit Agreement.  Each reference
in the Credit Agreement to this Agreement, hereunder, hereof, or words of
like import, and each reference to the Credit Agreement in any and all
instruments or documents delivered in connection therewith, shall be deemed to
refer to the Credit Agreement, as amended hereby.  8.7           Expenses.  Borrower shall pay all costs and expenses in
connection with the preparation of this Fifth Amendment and other related loan
documents, including, without limitation, reasonable attorneys fees and time
charges of attorneys who may be employees of Lender or any affiliate or parent
of Lender.  Borrower shall pay any and
all stamp and other taxes, UCC search fees, filing fees and other costs and
expenses in connection with the execution and  5


delivery of this Fifth Amendment and the other instruments and
documents to be delivered hereunder, and agrees to save Lender harmless from
and against any and all liabilities with respect to or resulting from any delay
in paying or omission to pay such costs and expenses.  8.8           Counterparts.  This Fifth Amendment may be executed in any
number of counterparts, all of which shall constitute one and the same
agreement.  [Signatures on following page]  6


IN
WITNESS WHEREOF, the parties hereto have executed this Fifth Amendment to the
Amended and Restated Credit Agreement and Reaffirmation of Guaranties as of the
date first above written.  Borrower:QUIXOTE CORPORATION,a Delaware corporation, as
  BorrowerBy:
  /s/ DANIEL P. GOREYName:
  Daniel P. GoreyTitle:
  Executive Vice President,
  Chief FinancialOfficer &
  TreasurerGuarantors:QUIXOTE TRANSPORTATION
  SAFETY, INC.
  TRANSAFE CORPORATIONENERGY ABSORPTION SYSTEMS,
  INC.ENERGY ABSORPTION SYSTEMS
  (AL) LLC
  SURFACE SYSTEMS, INC.NU-METRICS, INC.HIGHWAY INFORMATION
  SYSTEMS, INC.By:
  /s/ DANIEL P. GOREYName:
  Daniel P. GoreyTitle:
  Executive Vice
  President & TreasurerLender:BANK OF AMERICA, N.A., as
  successor by merger to LaSalle Bank National Association, a national banking
  associationBy:
  /s/ LORA BACKOFENName:
  Lora BackofenTitle:
  Senior Vice President  7


Schedule I  Organizational Identification Numbers  CORPORATION
  
  STATE
  
  STATE IDQuixote Corporation
  
  Delaware
  
  0720523Quixote Transportation
  Safety, Inc.
  
  Delaware
  
  2803660Transafe Corporation
  
  Delaware
  
  3197646Energy Absorption
  Systems, Inc.
  
  Delaware
  
  0904033Energy Absorption (AL) LLC
  
  Delaware
  
  3539333Surface Systems, Inc.
  
  Missouri
  
  00157025Nu-Metrics, Inc.
  
  Pennsylvania
  
  978728Highway Information
  Systems, Inc.
  
  Delaware
  
  2867376  8


SECOND AMENDED AND RESTATED REVOLVING LOAN NOTE  $15,000,000
  
  Chicago, IllinoisFebruary 9, 2009  FOR
VALUE RECEIVED, the undersigned, QUIXOTE CORPORATION, a Delaware corporation
(the Borrower), promises to pay to the
order of LaSalle Bank National Association and its registered assigns (the Lender), on November 1, 2009, the principal sum of
Fifteen Million Dollars and No/100 Dollars ($15,000,000.00), or, if less, the
aggregate unpaid principal amount of all loans made by the Lender to the
Borrower from time to time pursuant to that certain Amended and Restated Credit
Agreement, dated as of April 20, 2005, between the Borrower and Lender as
amended by the First Amendment to Amended and Restated Credit Agreement and
Reaffirmation of Guaranties, dated as of December 1, 2006, that certain
Second Amendment to Amended and Restated Credit Agreement and Reaffirmation of
Guaranties, dated as of March 15, 2007, that certain Third Amendment to
Amended and Restated Credit Agreement and Reaffirmation of Guaranties dated as of
November 7, 2007, that certain Fourth Amendment to Amended and Restated
Credit Agreement and Reaffirmation of Guaranties dated as of November 7,
2008 and that certain Fifth Amendment to Amended and Restated credit Agreement
dated as of the date hereof (together with all amendments, if any, from time to
time made thereto, the Credit Agreement).  The
Borrower agrees to pay interest on the principal hereof remaining from time to
time unpaid in accordance with Section 2.13 of the Credit Agreement.  All
payments of principal and interest on this Note shall be payable in lawful
currency of the United States of America at the Lenders office at 135 South
LaSalle Street, Chicago, Illinois 60603, in immediately available funds.  This
Note evidences indebtedness incurred under, and is subject to the terms and
provisions of, the Credit Agreement, to which reference is made for a statement
of those terms and provisions.  Should
the indebtedness represented by this Note or any part hereof be collected at
law or in equity or in bankruptcy, receivership, or other court proceedings, or
this Note be placed in the hands of attorneys for collection after maturity (by
declaration or otherwise), the undersigned agrees to pay, in addition to
principal and interest due and payable hereon, reasonable attorneys and
collection fees.  This
Note constitutes a renewal and restatement of, and replacement and substitution
for, that certain Amended and Restated Revolving Note, dated as of November 7,
2007 in the maximum principal amount of Forty Million and 00/100 Dollars
($40,000,000.00), executed by the Borrower and made payable to the order of the
Bank (the Prior Note).  The indebtedness evidenced by the Prior Note
is continuing indebtedness evidenced hereby, and nothing herein shall be deemed
to constitute a payment, settlement or novation of the Prior Note, or to
release or otherwise adversely affect any lien, mortgage or security interest
securing such indebtedness or any rights of the Bank against any guarantor,
surety or other party primarily or secondarily liable for such indebtedness.  [Signature on following page]  9


IN
WITNESS WHEREOF, the Borrower has executed this Note as of the date first above
written  QUIXOTE CORPORATIONBy:
  /s/DANIEL P. GOREYName
  Daniel P. GoreyTitle:
  Executive Vice President,
  Chief Financial Officer&
  Treasurer  10