<PAGE>

                                                                    EXHIBIT 4.18

                                 URS CORPORATION

                                SECOND AMENDMENT
                               TO CREDIT AGREEMENT

                  This SECOND AMENDMENT TO CREDIT AGREEMENT (this "AMENDMENT")
is dated as of November 6, 2003 and entered into by and among URS CORPORATION, a
Delaware corporation ("COMPANY"), THE FINANCIAL INSTITUTIONS LISTED ON THE
SIGNATURE PAGES HEREOF ("LENDERS") and CREDIT SUISSE FIRST BOSTON, as
administrative agent for Lenders ("ADMINISTRATIVE AGENT"), and is made with
reference to that certain Credit Agreement dated as of August 22, 2002, as
amended by that certain First Amendment to Credit Agreement dated as of January
30, 2003 (as so amended, and as further amended, modified, restated or otherwise
supplemented to the date hereof, the "CREDIT AGREEMENT"), by and among Company,
Lenders, CREDIT SUISSE FIRST BOSTON, as a Co-Lead Arranger and Administrative
Agent, WELLS FARGO BANK, NATIONAL ASSOCIATION, as a Co-Lead Arranger and
syndication agent for Lenders, and BNP PARIBAS, HARRIS TRUST & SAVINGS BANK and
THE ROYAL BANK OF SCOTLAND PLC, as co-documentation agents for Lenders.
Capitalized terms used herein without definition shall have the same meanings
herein as set forth in the Credit Agreement.

                                    RECITALS

                  WHEREAS, Company and Lenders desire to amend the Credit
Agreement as more particularly described below; and

                  WHEREAS, no event has occurred and is continuing or will
result from the consummation of the transactions contemplated by this Amendment
that would constitute an Event of Default or a Potential Event of Default:

                  NOW, THEREFORE, in consideration of the premises and the
agreements, provisions and covenants herein contained, the parties hereto agree
as follows:

         SECTION 1. AMENDMENTS TO THE CREDIT AGREEMENT

1.1      AMENDMENTS TO SECTION 1: DEFINITIONS

                  A.       Subsection 1.1 of the Credit Agreement is hereby
amended by deleting each of the definitions of "CONSOLIDATED EXCESS CASH FLOW",
"EXISTING SUBORDINATED INDENTURES" and "EXISTING SUBORDINATED NOTES" there from
in their entirety and substituting the following there for:

                           "CONSOLIDATED EXCESS CASH FLOW" means, for any
                  period, an amount equal to (i) Consolidated EBITDA for such
                  period minus (ii) the sum, without duplication, of the amounts
                  for such period of (a) to the extent not otherwise excluded
                  from Consolidated EBITDA, Cash expenditures during such period

                                       1
<PAGE>

                  relating to the Merger or any Permitted Acquisition applied
                  against accruals and reserves taken against goodwill
                  established in prior periods as approved by Administrative
                  Agent, (b) scheduled repayments of Consolidated Total Funded
                  Debt, (c) the aggregate amount of any repurchases or
                  redemptions of Existing Senior Subordinated Notes, Senior
                  Notes and/or Convertible Subordinated Notes of Company
                  pursuant to Section 7.5A(xi), (d) Consolidated Capital
                  Expenditures, (e) Consolidated Cash Interest Expense and (f)
                  the provision for current taxes based on income of Company and
                  its Subsidiaries on a consolidated basis and payable in Cash
                  with respect to such period.

                           "EXISTING SUBORDINATED INDENTURES" means (i) the
                  Indenture, dated as of March 16, 1989, between Thortec
                  International, Inc. and JPMorgan Chase Bank, successor to
                  MTrust Corp, National Association, as amended by Amendment
                  Number 1 and Amendment Number 2, as so amended and as may be
                  further amended from time to time to the extent permitted
                  under subsection 7.12B and (ii) the Convertible Subordinated
                  Note Indenture.

                           "EXISTING SUBORDINATED NOTES" means (i) Company's 8
                  5/8% Senior Subordinated Debentures due 2004 in the original
                  aggregate principal amount of $36,814,500 and the remaining
                  aggregate principal amount of $6,454,750 as of the Closing
                  Date and (ii) the Convertible Subordinated Notes.

                  B.       Subsection 1.1 of the Credit Agreement is hereby
                  further amended by adding thereto the following definitions in
                  proper alphabetical order:

                           "CONVERTIBLE SUBORDINATED NOTES" means Company's 6
                  1/2% Convertible Subordinated Notes due 2012 in the original
                  aggregate principal amount of $57,500,000 and the remaining
                  aggregate principal amount of $1,798,250 as of the Closing
                  Date.

                           "CONVERTIBLE SUBORDINATED NOTE INDENTURE" means the
                  Indenture, dated as of February 15, 1987, between Company and
                  The Bank of New York as assignee of First Interstate Bank of
                  California, as amended by Amendment Number 1, as so amended
                  and as may be further amended from time to time to the extent
                  permitted under subsection 7.12B.

                           "DISQUALIFIED STOCK" means any class or series of
                  Capital Stock of any Person that by its terms or otherwise is
                  (i) required to be redeemed prior to the Tranche B Term Loan
                  Maturity Date, (ii) redeemable at the option of the holder of
                  such class or series of Capital Stock at any time prior to the
                  Tranche B Term Loan Maturity Date or (iii) convertible into or
                  exchangeable for Capital Stock referred to in clause (i) or
                  (ii) above or Indebtedness having a scheduled maturity prior
                  to the Tranche B Term Loan Maturity Date; provided that any
                  Capital Stock that would not constitute Disqualified Stock but
                  for provisions thereof giving holders thereof the right to
                  require such Person to repurchase or redeem such Capital Stock
                  upon the occurrence of an "asset

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<PAGE>

                  sale" or "change of control" occurring prior to the Tranche B
                  Term Loan Maturity Date shall not constitute Disqualified
                  Stock if the "asset sale" or "change of control" provisions
                  applicable to such Capital Stock are no more favorable to the
                  holders of such Capital Stock than the provisions contained in
                  subsection 2.4B(iii) and subsection 8.11 and such Capital
                  Stock specifically provides that such Person will not
                  repurchase or redeem any such Capital Stock pursuant to such
                  provisions prior to Company's repayment of the Loans as may be
                  required to be paid pursuant to subsection 2.4B(iii) and
                  Section 8.

                           "MAXIMUM REPURCHASE AMOUNT" has the meaning assigned
                  to that term in subsection 7.5A(xiii).

                           "PERMITTED NOTE REPURCHASES" has the meaning assigned
                  to that term in subsection 7.5A(xii).

                           "VOLUNTARY PREPAYMENT AMOUNT" means, for any period,
                  the aggregate principal amount of Loans prepaid by Company
                  during such period pursuant to subsection 2.4B(i) or (ii)
                  (excluding prepayments of Revolving Loans except to the extent
                  the Revolving Loan Commitments are permanently reduced in
                  connection with such prepayments).

1.2      AMENDMENTS TO SECTION 2: AMOUNTS AND TERMS OF COMMITMENTS AND LOANS

                  A.       Subsection 2.4B(iii)(c) of the Credit Agreement is
                  hereby amended by (i) deleting the word "and" before clause
                  (3) thereof, and (ii) adding the following at the end of
                  clause (3):

                  ", and (4) issuances of Capital Stock (other than Disqualified
                  Stock), the Net Securities Proceeds of which are applied by
                  Company to Permitted Note Repurchases as expressly permitted
                  by subsection 7.5A(xii)"

                  B.       Subsection 2.4B(iii)(e) of the Credit Agreement is
                  hereby amended by deleting it in its entirety and substituting
                  the following therefor:

                                    "(e)     Prepayments and Reductions from
         Consolidated Excess Cash Flow. (1) In the event that there shall be a
         positive amount of Consolidated Excess Cash Flow for the two Fiscal
         Quarter period ending October 31, 2003, Company shall, no later than
         February 10, 2004, prepay the Loans in an aggregate amount equal to
         100% of such Consolidated Excess Flow minus any Voluntary Prepayment
         Amount for such period; and (2) in the event that there shall be a
         positive amount of Consolidated Excess Cash Flow for any Fiscal Year
         commencing with the Fiscal Year ending October 31, 2004, no later than
         100 days after the end of each such Fiscal Year, Company shall prepay
         the Loans in an aggregate amount equal to (A) 75% of such Consolidated
         Excess Cash Flow minus (B) any Voluntary Prepayment Amount for such
         Fiscal Year; provided, that commencing with the Fiscal Year ending
         October 31, 2004, such percentage shall be reduced to 50% of
         Consolidated Excess

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         Cash Flow for any Fiscal Year during which the Consolidated Leverage
         Ratio as of the last day of such Fiscal Year is less than 2.50:1.00."

1.3      AMENDMENTS TO SECTION 4: CONDITIONS TO LOANS AND LETTERS OF CREDIT

                  A.       Subsection 4.1C(i) of the Credit Agreement is hereby
                  amended by adding the following after the word "Schedule
                  4.1C":

                  ", Schedule 5.1D and Schedule 5.1E"

                  B.       Subsection 4.1C(ii) of the Credit Agreement is hereby
                  amended by adding the following after the word "Schedule
                  4.1C":

                  ", Schedule 5.1D and Schedule 5.1E"

1.4      AMENDMENTS TO SECTION 7: COMPANY'S NEGATIVE COVENANTS

                  A.       Subsection 7.1(ix) of the Credit Agreement is hereby
                  amended by deleting it in its entirety and substituting the
                  following therefor:

                           "(ix)    Company, its Subsidiaries and any Joint
                  Venture, as applicable, may remain liable with respect to
                  Indebtedness (including the amount of any committed lines of
                  credit) described on Schedule 7.1 of the Company Disclosure
                  Letter and any refinancings, refundings, renewals,
                  replacements or extensions thereof; provided that the
                  principal amount of such Indebtedness is not increased at the
                  time of such refinancing, refunding, renewal, replacement or
                  extension except by an amount equal to a reasonable premium or
                  other reasonable amount paid, and fees and expenses reasonably
                  incurred, in connection with such refinancing, refunding,
                  renewal, replacement or extension and by an amount equal to
                  any existing commitments unutilized thereunder;"

                  B.       Subsection 7.3(vi) of the Credit Agreement is hereby
                  amended by deleting it in its entirety and substituting the
                  following therefor:

                           "(vi)    Company and Subsidiary Guarantors may (x)
                  continue to own the existing Investments reflected on Schedule
                  4.1C, Schedule 5.1D and Schedule 5.1E of the Company
                  Disclosure Letter, and (y) make and own additional equity
                  Investments in Subsidiary Guarantors;"

                  C.       Subsection 7.5A of the Credit Agreement is hereby
                  amended by (i) deleting the word "and" before clause (xi)
                  thereof, and (ii) amending and restating clause (xi) in its
                  entirety as follows:

                  "(xi) Company may repurchase or redeem Existing Senior
                  Subordinated Notes, Senior Notes, Convertible Subordinated
                  Notes and/or Capital Stock of Company in an aggregate amount
                  not to exceed $25,000,000 (without regard

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                  to underwriting discounts and commissions and other reasonable
                  costs and expenses associated therewith, including reasonable
                  legal fees and expenses), provided that after giving effect to
                  any such redemption of Existing Senior Subordinated Notes
                  and/or Senior Notes and/or Convertible Subordinated Notes,
                  such redemption is made in accordance with the terms of the
                  Existing Senior Subordinated Indenture, the Senior Indenture
                  and/or the Convertible Subordinated Note Indenture,
                  respectively;"

                  D.       Subsection 7.5A of the Credit Agreement is hereby
                  further amended by adding the following provisions at the end
                  of clause (xi):

                  "(xii) Company may repurchase or redeem Existing Senior
                  Subordinated Notes and/or Senior Notes and/or Convertible
                  Subordinated Notes (any such redemption being made in
                  accordance with the terms of the Existing Senior Subordinated
                  Indenture, the Senior Indenture and/or the Convertible
                  Subordinated Note Indenture, respectively) in an aggregate
                  amount not to exceed $220,000,000 of any Net Securities
                  Proceeds from the issuance of Capital Stock (other than
                  Disqualified Stock) of Company, provided that the repurchase
                  or redemption price of such Existing Senior Subordinated Note
                  and/or Senior Notes and/or Convertible Notes (exclusive of
                  underwriting discounts and commissions and other reasonable
                  costs and expenses associated therewith, including reasonable
                  legal fees and expenses) shall not exceed the higher of (A)
                  110% of the principal amount (par value) and (B) the
                  redemption price (call price), in each case plus any accrued
                  and unpaid interest thereon to the repurchase or redemption
                  date of such Existing Senior Subordinated Notes and/or Senior
                  Notes and/or Convertible Subordinated Notes, as the case may
                  be, in effect at the time of such repurchase or redemption
                  (any such repurchases or redemptions in compliance with this
                  subsection 7.5A(xii) being "PERMITTED NOTE REPURCHASES"); and
                  (xiii) during any Fiscal Quarter ending on or after April 30,
                  2004, Company may repurchase or redeem Existing Senior
                  Subordinated Notes and/or Senior Notes and/or Convertible
                  Subordinated Notes (any such redemption being made in
                  accordance with the terms of the Existing Senior Subordinated
                  Indenture, the Senior Indenture and/or the Convertible
                  Subordinated Note Indenture, respectively) in an amount equal
                  to 25% of Consolidated Excess Cash Flow for the three-month
                  period ended as of the last day of the most recently completed
                  Fiscal Quarter (the "MAXIMUM REPURCHASE AMOUNT"); provided
                  that the Consolidated Leverage Ratio as of the last day of the
                  most recently completed Fiscal Quarter, after giving effect to
                  the proposed repurchase or redemption and any other
                  repurchases or redemptions previously consummated during such
                  Fiscal Quarter as though they had occurred on the last day of
                  the most recently completed Fiscal Quarter, is less than 3:00
                  to 1:00; provided further that (a) such percentage shall be
                  increased to 50% of Consolidated Excess Cash Flow during any
                  Fiscal Quarter for which the Consolidated Leverage Ratio as of
                  the end of the most recently completed Fiscal Quarter, after
                  giving effect to the proposed repurchase or redemption and any
                  other repurchases or redemptions previously consummated during
                  such Fiscal Quarter as though they had

                                       5
<PAGE>

                  occurred on the last day of the most recently completed Fiscal
                  Quarter, is less than 2:50 to 1:00, (b) the Maximum Repurchase
                  Amount for any Fiscal Quarter shall be increased by an amount
                  equal to the excess, if any, of the Maximum Repurchase Amount
                  for each of the previous three Fiscal Quarters (without giving
                  effect to any adjustment in accordance with subclauses (b) and
                  (c) of this proviso, and solely to the extent that such
                  previous Fiscal Quarters ended on or after January 31, 2004)
                  over the actual amount applied to repurchases or redemptions
                  during such previous Fiscal Quarters, and (c) the Maximum
                  Repurchase Amount for any Fiscal Quarter shall be decreased by
                  any negative Maximum Repurchase Amount for each of the
                  previous three Fiscal Quarters (without giving effect to any
                  adjustment in accordance with subclauses (b) and (c) of this
                  proviso, and solely to the extent that such previous Fiscal
                  Quarters ended on or after January 31, 2004)."

         SECTION 2. CONDITIONS TO EFFECTIVENESS

                  Section 1 of this Amendment shall become effective as of
                  September 15, 2003 (the "SECOND AMENDMENT EFFECTIVE DATE")
                  only upon the satisfaction of all of the following conditions
                  precedent:

                  A.       On or before November 6, 2003, Company shall deliver
                  to Lenders (or to Administrative Agent for Lenders) the
                  following, each, unless otherwise noted, dated November 6,
                  2003:

                           1.       Certified copies of its Certificate of
                  Incorporation, together with a good standing certificate from
                  the Secretary of State of the State of Delaware, each dated a
                  recent date prior to November 6, 2003;

                           2.       A certificate, dated as of November 6, 2003,
                  of its corporate secretary or an assistant secretary,
                  certifying that there have been no changes in its Bylaws from
                  the form of Bylaws previously delivered to Lenders;

                           3.       Resolutions of its Board of Directors
                  approving and authorizing the execution, delivery, and
                  performance of this Amendment, certified as of November 6,
                  2003 by its corporate secretary or an assistant secretary as
                  being in full force and effect without modification or
                  amendment;

                           4.       Signature and incumbency certificates of its
                  officers executing this Amendment; and

                           5.       Executed copies of this Amendment.

                  B.       Requisite Lenders shall have executed this Amendment.

                  C.       On or before November 6, 2003, all corporate and
                  other proceedings taken or to be taken in connection with the
                  transactions contemplated hereby shall be satisfactory in form
                  and substance to Administrative Agent and such counsel, and
                  Administrative Agent and such counsel shall have received all

                                       6
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                  such counterpart originals or certified copies of such
                  documents as Administrative Agent may reasonably request.

                  D.       Company shall pay to each Lender executing this
                  Amendment by 5:00 p.m., New York time, on November 6, 2003 an
                  amendment fee equal to 0.10% of the sum of such Lender's
                  Tranche A Term Loan Exposure plus such Lender's Tranche B Term
                  Loan Exposure plus such Lender's Revolving Loan Exposure.

         SECTION 3. COMPANY'S REPRESENTATIONS AND WARRANTIES

         In order to induce Lenders to enter into this Amendment and to amend
         the Credit Agreement in the manner provided herein, Company represents
         and warrants to each Lender that the following statements are true,
         correct and complete as of the date of this Amendment:

                  A.       CORPORATE POWER AND AUTHORITY. Company has all
                  requisite corporate power and authority to enter into this
                  Amendment and to carry out the transactions contemplated by,
                  and perform its obligations under, the Credit Agreement as
                  amended by this Amendment (the "AMENDED AGREEMENT").

                  B.       AUTHORIZATION OF AGREEMENTS. The execution and
                  delivery of this Amendment and the performance of the Amended
                  Agreement have been duly authorized by all necessary corporate
                  action on the part of Company.

                  C.       NO CONFLICT. The execution and delivery by Company of
                  this Amendment and the performance by Company of the Amended
                  Agreement do not and will not (i) violate any provision of any
                  law or any governmental rule or regulation applicable to
                  Company or any of its Subsidiaries, the Certificate or
                  Articles of Incorporation or Bylaws of Company or any of its
                  Subsidiaries or any order, judgment or decree of any court or
                  other agency of government binding on Company or any of its
                  Subsidiaries, (ii) conflict with, result in a breach of or
                  constitute (with due notice or lapse of time or both) a
                  default under any Contractual Obligation of Company or any of
                  its Subsidiaries in any manner that would be likely to result
                  in a Material Adverse Effect, (iii) result in or require the
                  creation or imposition of any Lien upon any of the properties
                  or assets of Company or any of its Subsidiaries (other than
                  Liens created under any of the Loan Documents in favor of
                  Administrative Agent on behalf of Lenders or Permitted
                  Encumbrances), or (iv) require any approval of stockholders or
                  any approval or consent of any Person under any Contractual
                  Obligation of Company or any of its Subsidiaries.

                  D.       GOVERNMENTAL CONSENTS. The execution and delivery by
                  Company of this Amendment and the performance by Company of
                  the Amended Agreement do not and will not require any
                  registration with, consent or approval of, or notice to, or
                  other action to, with or by, any federal, state or other
                  governmental authority or regulatory body.

                                       7
<PAGE>

                  E.       BINDING OBLIGATION. This Amendment has been duly
                  executed and delivered by Company and this Amendment and the
                  Amended Agreement are the legally valid and binding
                  obligations of Company, enforceable against Company in
                  accordance with their respective terms, except as may be
                  limited by bankruptcy, insolvency, reorganization, moratorium
                  or similar laws relating to or limiting creditors' rights
                  generally or by equitable principles relating to
                  enforceability.

                  F.       INCORPORATION OF REPRESENTATIONS AND WARRANTIES FROM
                  CREDIT AGREEMENT. The representations and warranties contained
                  in Section 5 of the Credit Agreement are and will be true,
                  correct and complete in all material respects on and as of the
                  date hereof to the same extent as though made on and as of
                  such date, except to the extent such representations and
                  warranties specifically relate to an earlier date, in which
                  case they were true, correct and complete in all material
                  respects on and as of such earlier date.

                  G.       ABSENCE OF DEFAULT. No event has occurred and is
                  continuing or will result from the consummation of the
                  transactions contemplated by this Amendment that would
                  constitute an Event of Default or a Potential Event of
                  Default.

         SECTION 4. MISCELLANEOUS

                  A.       REFERENCE TO AND EFFECT ON THE CREDIT AGREEMENT AND
                  THE OTHER LOAN DOCUMENTS.

                  (i)      On and after the Second Amendment Effective Date,
                  each reference in the Credit Agreement to "this Agreement",
                  "hereunder", "hereof", "herein" or words of like import
                  referring to the Credit Agreement, and each reference in the
                  other Loan Documents to the "Credit Agreement", "thereunder",
                  "thereof" or words of like import referring to the Credit
                  Agreement shall mean and be a reference to the Amended
                  Agreement.

                  (ii)     Except as specifically amended by this Amendment, the
                  Credit Agreement and the other Loan Documents shall remain in
                  full force and effect and are hereby ratified and confirmed.

                  (iii)    The execution, delivery and performance of this
                  Amendment shall not, except as expressly provided herein,
                  constitute a waiver of any provision of, or operate as a
                  waiver of any right, power or remedy of Administrative Agent
                  or any Lender under, the Credit Agreement or any of the other
                  Loan Documents.

                  B.       FEES AND EXPENSES. Company acknowledges that all
                  costs, fees and expenses as described in subsection 10.2 of
                  the Credit Agreement incurred by Administrative Agent and its
                  counsel with respect to this Amendment and the documents and
                  transactions contemplated hereby shall be for the account of
                  Company.

                                       8
<PAGE>

                  C.       HEADINGS. Section and subsection headings in this
                  Amendment are included herein for convenience of reference
                  only and shall not constitute a part of this Amendment for any
                  other purpose or be given any substantive effect.

                  D.       APPLICABLE LAW. THIS AMENDMENT AND THE RIGHTS AND
                  OBLIGATIONS OF THE PARTIES HEREUNDER SHALL BE GOVERNED BY, AND
                  SHALL BE CONSTRUED AND ENFORCED IN ACCORDANCE WITH, THE
                  INTERNAL LAWS OF THE STATE OF NEW YORK (INCLUDING WITHOUT
                  LIMITATION SECTION 5-1401 OF THE GENERAL OBLIGATIONS LAW OF
                  THE STATE OF NEW YORK), WITHOUT REGARD TO CONFLICTS OF LAWS
                  PRINCIPLES.

                  E.       COUNTERPARTS. This Amendment may be executed in any
                  number of counterparts and by different parties hereto in
                  separate counterparts, each of which when so executed and
                  delivered shall be deemed an original, but all such
                  counterparts together shall constitute but one and the same
                  instrument; signature pages may be detached from multiple
                  separate counterparts and attached to a single counterpart so
                  that all signature pages are physically attached to the same
                  document.

         SECTION 5. ACKNOWLEDGEMENT AND CONSENT BY GUARANTORS

                  Each guarantor listed on the signature pages hereof
                  ("SUBSIDIARY GUARANTORS") hereby acknowledges that it has read
                  this Amendment and consents to the terms thereof, and hereby
                  confirms and agrees that, notwithstanding the effectiveness of
                  this Amendment, the obligations of each Subsidiary Guarantor
                  under its applicable Subsidiary Guaranty shall not be impaired
                  or affected and the applicable Subsidiary Guaranty is, and
                  shall continue to be, in full force and effect and is hereby
                  confirmed and ratified in all respects. Each Subsidiary
                  Guarantor further agrees that nothing in the Credit Agreement,
                  this Amendment or any other Loan Document shall be deemed to
                  require the consent of such Subsidiary Guarantor to any future
                  amendment to the Credit Agreement.

                  [Remainder of page intentionally left blank]

                                       9
<PAGE>

                  IN WITNESS WHEREOF, the parties hereto have caused this
Amendment to be duly executed and delivered by their respective officers
thereunto duly authorized as of the date first written above.

                                    URS CORPORATION,
                                    a Delaware corporation

                                    /s/ Kent P. Ainsworth
                                    --------------------------------------------
                                    Name:  Kent P. Ainsworth
                                    Title: Executive Vice President and Chief
                                           Financial Officer

                                    CREDIT SUISSE FIRST BOSTON,
                                    Individually and as Administrative Agent

                                     /s/ S. William Fox
                                    --------------------------------------------
                                    Title: Director

                                     /s/ David J. Dodd
                                    --------------------------------------------
                                    Title: Associate

                                    AMAN ENVIRONMENTAL CONSTRUCTION, INC.,
                                    a California corporation

                                    /s/ Jeffrey M. Kissel
                                    --------------------------------------------
                                    Name:  Jeffrey M. Kissel
                                    Title: Chief Financial Officer

                                    BANSHEE CONSTRUCTION COMPANY, INC.,
                                    a California corporation

                                    /s/ Michael T. Orear
                                    --------------------------------------------
                                    Name:  Michael T. Orear
                                    Title: President

                                       10
<PAGE>

                                    CLEVELAND WRECKING COMPANY,
                                    a California corporation

                                    /s/ James Sheridan
                                    --------------------------------------------
                                    Name:  James Sheridan
                                    Title: President

                                    O'BRIEN-KREITZBERG INC.,
                                    a California corporation

                                    /s/ Jeffrey M. Kissel
                                    --------------------------------------------
                                    Name:  Jeffrey M. Kissel
                                    Title: Chief Financial Officer

                                    RADIAN INTERNATIONAL LLC,
                                    a Delaware limited liability company

                                    /s/ David C. Nelson
                                    --------------------------------------------
                                    Name:  David C. Nelson
                                    Title: Vice President and Treasurer

                                    SIGNET TESTING LABORATORIES, INC.,
                                    a Delaware corporation

                                    /s/ Kent P. Ainsworth
                                    --------------------------------------------
                                    Name:  Kent P. Ainsworth
                                    Title: Executive Vice President,
                                           Chief Financial Officer and Secretary

                                    URS CONSTRUCTION SERVICES, INC.,
                                    a Florida corporation

                                    /s/ Kent P. Ainsworth
                                    --------------------------------------------
                                    Name:  Kent P. Ainsworth
                                    Title: Executive Vice President and
                                           Chief Executive Officer

                                       11
<PAGE>

                                    URS CORPORATION,
                                    a Nevada corporation

                                    /s/ David C. Nelson
                                    --------------------------------------------
                                    Name:  David C. Nelson
                                    Title: Vice President and Treasurer

                                    URS CORPORATION GREAT LAKES,
                                    a Michigan corporation

                                    /s/ Kent P. Ainsworth
                                    --------------------------------------------
                                    Name:  Kent P. Ainsworth
                                    Title: Executive Vice President and
                                           Chief Financial Officer

                                    URS CORPORATION GROUP CONSULTANTS,
                                    a New York corporation

                                    /s/ David C. Nelson
                                    --------------------------------------------
                                    Name:  David C. Nelson
                                    Title: Vice President and Treasurer

                                    URS CORPORATION-MARYLAND,
                                    a Maryland corporation

                                    /s/ David C. Nelson
                                    --------------------------------------------
                                    Name:  David C. Nelson
                                    Title: Vice President and Treasurer

                                    URS CORPORATION - OHIO,
                                    an Ohio corporation

                                    /s/ David C. Nelson
                                    --------------------------------------------
                                    Name:  David C. Nelson
                                    Title: Vice President and Treasurer

                                       12
<PAGE>

                                    URS CORPORATION SOUTHERN,
                                    a California corporation

                                    /s/ David C. Nelson
                                    --------------------------------------------
                                    Name:  David C. Nelson
                                    Title: Vice President and Treasurer

                                    URS GROUP, INC.,
                                    a Delaware corporation

                                    /s/ David C. Nelson
                                    --------------------------------------------
                                    Name:  David C. Nelson
                                    Title: Vice President and Assistant
                                           Treasurer

                                    URS OPERATING SERVICES, INC.,
                                    a Delaware corporation

                                    /s/ P.J. Pedalino
                                    --------------------------------------------
                                    Name:  P. J. Pedalino
                                    Title: Vice President and Controller

                                    URS HOLDINGS, INC.,
                                    a Delaware corporation

                                    /s/ David C. Nelson
                                    --------------------------------------------
                                    Name:  David C. Nelson
                                    Title: Vice President and Treasurer

                                    URS INTERNATIONAL INC.,
                                    a Delaware corporation

                                    /s/ David C. Nelson
                                    --------------------------------------------
                                    Name:  David C. Nelson
                                    Title: Vice President and Treasurer

                                       13
<PAGE>

                                    LEAR SIEGLER SERVICES, INC.,
                                    a Delaware corporation

                                    /s/ Kent P. Ainsworth
                                    --------------------------------------------
                                    Name:  Kent P. Ainsworth
                                    Title: Executive Vice President and
                                           Chief Financial Officer

                                    EG&G DEFENSE MATERIALS, INC.,
                                    a Utah corporation

                                    /s/ William Neeb
                                    --------------------------------------------
                                    Name:  William Neeb
                                    Title: Vice President

                                    EG&G TECHNICAL SERVICES, INC.,
                                    a Delaware corporation

                                    /s/ Kent P. Ainsworth
                                    --------------------------------------------
                                    Name:  Kent P. Ainsworth
                                    Title: Executive Vice President and
                                           Chief Financial Officer

                                    D&M CONSULTING ENGINEERS, INC.,
                                    a Delaware corporation

                                    /s/ Kent P. Ainsworth
                                    --------------------------------------------
                                    Name:  Kent P. Ainsworth
                                    Title: Executive Vice President and
                                           Chief Financial Officer

                                    E.C. DRIVER & ASSOCIATES, INC.,
                                    a Florida corporation

                                    /s/ Kent P. Ainsworth
                                    --------------------------------------------
                                    Name:  Kent P. Ainsworth
                                    Title: Executive Vice President and
                                           Chief Financial Officer

                                       14
<PAGE>

                                    LEAR SIEGLER LOGISTICS INTERNATIONAL, INC.,
                                    a Delaware corporation

                                    /s/ Kent P. Ainsworth
                                    --------------------------------------------
                                    Name:  Kent P. Ainsworth
                                    Title: Attorney-in-fact

                                    RADIAN ENGINEERING, INC.,
                                    a New York corporation

                                    /s/ Kent P. Ainsworth
                                    --------------------------------------------
                                    Name:  Kent P. Ainsworth
                                    Title: Executive Vice President.
                                           Chief Financial Officer and Secretary

                                    URS CORPORATION AES.,
                                    a Connecticut corporation

                                    /s/ Kent P. Ainsworth
                                    --------------------------------------------
                                    Name:  Kent P. Ainsworth
                                    Title: Executive Vice President and
                                           Chief Financial Officer

                                    URS CORPORATION ARCHITECTURE-NC, P.C.,
                                    a North Carolina corporation

                                     /s/ Kent P. Ainsworth
                                    --------------------------------------------
                                    Name:  Kent P. Ainsworth
                                    Title: Executive Vice President and
                                           Chief Financial Officer

                                    URS CORPORATION - NEW YORK,
                                    a New York corporation

                                    /s/ Kent P. Ainsworth
                                    --------------------------------------------
                                    Name:  Kent P. Ainsworth
                                    Title: Executive Vice President and
                                           Chief Financial Officer

                                       15
<PAGE>

                                    URS RESOURCES, LLC,
                                    a Delaware limited liability company

                                    /s/ Kent P. Ainsworth
                                    --------------------------------------------
                                    Name:  Kent P. Ainsworth
                                    Title: Attorney-in-fact

                                    WELLS FARGO BANK, N.A.,
                                    as a Lender

                                    /s/ Peter D. Gruebele_
                                    --------------------------------------------
                                    Name:  Peter D. Gruebele
                                    Title: Senior Vice President

                                       16