<PAGE>

                        FOURTH AMENDMENT TO LEASE


      THIS FOURTH AMENDMENT TO LEASE is made and entered into as of the 18th
day of September, 1996, between UNITED INSURANCE COMPANY OF AMERICA, as
"Landlord", and QUIXOTE CORPORATION, as "Tenant".

      WHEREAS, Landlord and Tenant previously entered into a Lease (the
"Lease"), pursuant to which Landlord leased to Tenant, and Tenant leased from
Landlord, the premises commonly known as Suite 3000 on the 30th floor of the
One East Wacker Drive Building, Chicago, Illinois, on the terms and conditions
therein set forth.

      WHEREAS, Landlord and Tenant thereafter entered into an amendment to the
Lease (the "First Lease Amendment");, pursuant to which Suite 2320, located on
the 23rd floor of the One East Wacker Drive Building, Chicago, Illinois, was
added to the Premises under the Lease, on the terms and conditions set forth
in the First Lease Amendment.

      WHEREAS, Landlord and Tenant thereafter entered into a second amendment
to the Lease (the "Second Lease Amendment"), pursuant to which Suite 2320 was
deleted from the Premises under the Lease, on the terms and conditions set
forth in the Second Lease Amendment.

      WHEREAS, Landlord and Tenant thereafter entered into a third amendment
to the lease (the "Third Lease Amendment"), pursuant to which Suite 2900,
located on the 29th floor of the One East Wacker Drive Building, Chicago,
Illinois, was added to the Premises under the Lease, on the terms and
conditions set forth in the Third Lease Amendment.

<PAGE>

      WHEREAS, Tenant has expressed it desire to add additional space to the
Premises under the Lease, and Landlord and Tenant have reached an agreement
with respect thereto.

      NOW, THEREFORE, in consideration of the reciprocal agreements herein
contained, and other good and valuable consideration, the adequacy and receipt
whereof hereby is acknowledged, the parties hereto agree as follows:

      1.   The above recitals are incorporated in and made an express part of
this Fourth Amendment to Lease.

      2.   As of October 1, 1996, certain space located on the 29th floor of
the One East Wacker Drive Building, Chicago, Illinois, known as Suite 2910 and
shown on Exhibit A-3 attached hereto and made a part hereof (the "Expansion
Space") shall be added to the Premises under the Lease.

      3.   Effective October 1, 1996, the Base Rent that is payable by Tenant
under the Lease shall be increased by the following amounts for the following
periods:

                  DATE                ANNUAL RENT        MONTHLY RENT
                  ----                -----------        ------------
            10/1/96 - 9/30/97          $15,080.00          $1,256.67
            10/1/97 - 9/30/98          $15,381.60          $1,281.80
            10/1/98 - 9/30/99          $15,689.23          $1,307.44
            10/1/99 - 9/30/00          $16,003.02          $1,333.58
            10/1/00 - 9/30/01          $16,323.08          $1,360.26
            10/1/01 - 9/30/02          $16,649.54          $1,387.46
            10/1/02 - 9/30/03          $16,982.53          $1,415.21
            10/1/03 - 2/28/04          $17,322.18*         $1,443.51
* on an annualized basis


     If the Expansion Space is ready for occupancy hereunder and Tenant takes
possession of the same prior to October 1, 1996, the 


                                      -2-

<PAGE>


Base Rent shall be increased for the period prior to October 1, 1996 by an 
amount equal to $1,256.67 divided by 31 multiplied by the number of remaining 
days in October of 1996 from and after the date that Tenant takes possession; 
and Tenant's Proportionate Share shall be increased as hereinafter provided 
as of the date that Tenant so takes possession.

      4.   Effective October 1, 1996, Tenant's Proportionate Share of
Additional Rent under the Lease shall be increased by 0.005841.

      5.   If Tenant so requests (in writing) of Landlord on or before April 
1, 1997, and if Tenant obtains approved Plans therefor on or before May 1, 
1997, Landlord shall cause the Expansion Space to be improved in accordance 
with the terms and conditions of the Work Letter which is attached hereto and 
made a part hereof.  If Tenant does not so request that the Expansion Space 
be improved or does not obtain approved Plans therefor, as aforesaid, the 
amount of the "construction allowance" set forth in the Work Letter shall be 
credited against the next Rent payments that otherwise would be due from 
Tenant. Likewise, if the Expansion Space is improved as herein provided, but 
the cost of the Work performed pursuant to the Work Letter is less than the 
amount of the "construction allowance" set forth therein, the unused portion 
of the "construction allowance" shall be credited against the next Rent 
payments that otherwise would be due from Tenant.

      6.   Except as expressly stated herein, the Lease shall be and remain in
full force and effect.


                                      -3-

<PAGE>



     IN WITNESS WHEREOF, the parties have executed this Fourth Amendment to
Lease as of the date and year above first written.

LANDLORD:                          TENANT:

UNITED INSURANCE COMPANY           QUIXOTE CORPORATION
OF AMERICA


By:/s/David Bengston               By:  /s/ Daniel P. Gorey
   -------------------------            ------------------------------
Its: Vice President                Its: Cheif Financial Officer
                                        Vice President & Controller










                                      -4-

<PAGE>

                              EXHIBIT B


Attached to and forming part of the Lease by and between UNITED INSURANCE
COMPANY OF AMERICA, Landlord, and QUIXOTE CORPORATION, Tenant, leasing Suite
2910 on the 29th floor of the ONE EAST WACKER BUILDING.


                             WORK LETTER



      RE:   ONE EAST WACKER BUILDING

Gentlemen:

      You ("Tenant") and we ("Landlord") are executing simultaneously herewith
a written lease (the "Lease") covering the space referred to above, as more
particularly described in the Lease (the "Premises").

      To induce Tenant to enter into the Lease and in consideration of the
mutual covenants therein and hereinafter contained, Landlord and Tenant
mutually agree as follows:
      
         1.   Landlord, at its expense up to a maximum expenditure of 
      $36,192.00, will improve the Premises utilizing skilled tradesmen 
      practicing good workmanship and using good quality materials and will 
      deliver the Premises to Tenant, free and clear of all liens and 
      encumbrances arising from the performance of the Work, according to the 
      plan and specifications to be prepared by an architect mutually 
      acceptable to Landlord and Tenant ("Plans"). Any amendments to the 
      Plans shall not change the scope of the Work or the character and 
      design of the Premises as reflected in the original Plans and shall not 
      require any structural alterations, any alterations to any HVAC, 
      electrical or plumbing or other systems servicing portions of the 
      Building other than the Premises, or any alterations involving 
      washrooms or public areas on the 29th floor.  The original Plans and 
      all amendments thereto must be approved in writing by Landlord, which 
      approval will not be unreasonably withheld.  All labor, services and 
      materials required by the Plans are herein referred to as "the Work".

         All costs in excess of said $36,192.00 shall be paid by Tenant.  
      Tenant agrees to deposit into an escrow account with Landlord, no later 
      than five (5) business days after any such excess is estimated, an 
      amount equal to such excess or additional costs.  Periodic payments 
      shall be made to Landlord out of the escrow in sufficient time to allow 
      Landlord to make payments for such excess.

         Upon substantial completion, the Architect, Landlord and Tenant 
      shall inspect the Premises and prepare and sign a "punchlist" setting 
      forth all incomplete or defective work items, which Landlord will use 
      its best efforts to repair 


                               EXHIBIT B - PAGE 1

<PAGE>


      and/or correct or to cause to be repaired and/or corrected within sixty 
      (60) days, subject to labor problems, availability of materials, 
      weather conditions, acts of God, transportation problems and 
      other causes beyond Landlord's reasonable control.

      Landlord agrees to repair and/or correct or cause to be repaired and/or
corrected any latent defects in labor or materials furnished by Landlord in
the improvement of the Premises which are discovered and reported in writing
to Landlord within thirty (30) days after the substantial completion of all of
the Work.  Landlord will use its best efforts to correct any such latent
defects within thirty (30) days after notice of such defect is received.

      Upon completion of the foregoing repair and corrective work, Landlord
will assign to Tenant, to the fullest extent assignable, all manufacturer's
and contractor's warranties and guarantees with respect to the Work.  To the
extent not assignable, Landlord agrees to make or allow Tenant in Landlord's
name to make all claims under such warranties and guarantees.

      2.   Tenant shall have the right to inspect the Work from time to time,
provided that Tenant does not interfere with the progress of the Work.

      3.   All procedures and requirements relating to extras, changes and
deletions in the Work, and the costs thereof, shall be governed by the terms
of the construction contract documents.  No extras, changes, or deletions in
the Work shall be permitted without the prior written consent of Landlord,
unless required by manufacturer's recommendations or instructions, by statute,
law, ordinance or governmental regulation, by unavailability of equipment or
materials, or by necessity to provide a proper finished product.  No extras,
changes, or deletions in the Work materially affecting any structural
elements, windows, elevators or HVAC, electrical, plumbing or other systems
serving portions of the Building other than the Premises or affecting the
cost, scope, character or design of the Work shall be permitted without the
prior written consent of Landlord, which Landlord may withhold in its sole
discretion.

      4.   Miscellaneous:

           a.   The Work shall be done by Landlord and/or its designers, 
      contractors and subcontractors, in accordance with the terms, 
      conditions, and provisions herein contained.

           b.   Except as herein expressly set forth, Landlord has no 
      agreement with Tenant and has no obligation to perform or provide any 
      other work with respect to the Premises.

              Any other work in the Premises which may be permitted by 
      Landlord pursuant to the terms and 

                               EXHIBIT B - PAGE 2

<PAGE>



      conditions of the Lease shall be done at Tenant's sole cost and expense 
      and in accordance with the terms and conditions of the Lease and this 
      Work Letter (to the extent applicable).

           c.   If the Plans for the Work require construction or 
      installation of more fire hose cabinets than the number regularly 
      provided by the Landlord in the core of the Building, the Tenant agrees 
      to pay all costs and expenses in connection with the construction or 
      installation of such additional fire hose cabinets.

           d.   Under no circumstances shall the Lease Commencement Date or 
      Tenant's obligation to commence paying rent be delayed in whole or in 
      part because of any delay or cost arising or incurred in connection 
      with any extra, change or deletion requested or caused by Tenant or its 
      agents or contractors at any time to any of the Work.

           e.   Time is of the essence under this Agreement.

           f.   Any person signing this Letter of Agreement on behalf of the 
      Tenant warrants and represents that he has the express authority of 
      Tenant to do so.

           g.   This Work Letter shall not be deemed applicable to any 
      additional space added to the original Premises at any time, whether by 
      any options under the Lease or otherwise, or to any portion of the 
      original Premises or any additions thereto in the event of a renewal or 
      extension of the original Term of the Lease, whether obtained pursuant 
      to any options under the Lease or otherwise, unless expressly so 
      provided in the Lease or a written amendment or supplement thereto.

           h.   This Letter of Agreement shall be binding upon and inure to 
      the benefit of the parties hereto and their respective heirs, legal 
      representatives, successors and assigns.

                                    UNITED INSURANCE COMPANY OF AMERICA


                                    By: /s/ David Bengston
                                       -----------------------------
                                    Date: December 10, 1996
AGREED TO AND ACCEPTED THIS

4th DAY OF December, 1996.


QUIXOTE CORPORATION

By:/s/ Daniel P. Gorey
--------------------------

                               EXHIBIT B - PAGE 3