<PAGE>   1
                                                                   Exhibit 10.15

                               FIRST AMENDMENT TO
                                CREDIT AGREEMENT


         THIS FIRST AMENDMENT TO CREDIT AGREEMENT (this "Amendment") is made and
dated as of the 14th day of December, 1998, by and among RED ROOF INNS, INC., a
Delaware corporation (the "Borrower"), the commercial lending institutions
listed on the signature pages hereof (collectively, the "Lenders"), CIBC
Oppenheimer Corp. (formerly known as CIBC Wood Gundy Securities Corp.) ("CIBC
Oppenheimer") and The Huntington National Bank ("HNB"), as arrangers (herein, in
such capacity, the "Arrangers"), HNB, as administrative and collateral agent
(herein, in such capacity, the "Administrative Agent" or "Collateral Agent") and
CIBC Oppenheimer, as syndication and documentation agent (herein, in such
capacity, the "Syndication and Documentation Agent"; the Syndication and
Documentation Agent and the Administrative Agent are herein collectively called
the "Agents").

                                    RECITALS
                                    --------

         A. The Borrower and the Lenders entered into that certain $250,000,000
Amended and Restated Credit Agreement dated as of May 21, 1997 (the "Credit
Agreement"), pursuant to which the Lenders agreed to extend credit to the
Borrower on the terms and subject to the conditions set forth therein.

         B. The Borrower, the Lenders and the Agents desire to amend certain
terms and conditions of the Credit Agreement pursuant to this Amendment.

         NOW, THEREFORE, in consideration of the above Recitals and for other
good and valuable consideration, the receipt and adequacy of which are hereby
acknowledged, the parties hereto hereby agree to amend the Credit Agreement as
follows:


                                    AGREEMENT
                                    ---------

         1. The Credit Agreement is hereby amended as follows:

         (a) There shall be added to Section 1.1 of the Credit Agreement, in
appropriate alphabetical sequence, the following definitions:

         "Completion Guaranty" means a guaranty given by the Borrower or any
         Guarantor to the holder of Indebtedness of, or an obligee of, an owner,
         operator or licensee of a Red Roof Inn hotel which obligates the
         Borrower or such Guarantor (a) to cause the completion of construction
         of a Red Roof Inn hotel or (b) to provide

<PAGE>   2
         funding for all or a portion of any construction cost
         overruns with respect thereto.

         "Joint Venture" means a single-purpose corporation, partnership,
         limited liability company, joint venture or other similar legal
         arrangement (whether created by contract or conducted through a
         separate legal entity) in which the Borrower or any of its Subsidiaries
         owns 50% or less of the equity interests entitled to vote in the
         election of directors, managers or trustees thereof and in which the
         Borrower or any of its Subsidiaries participates with another Person in
         order to conduct a common venture or enterprise.

         (b) The definition of the term "Contingent Liability" in Section 1.1 of
the Credit Agreement is hereby amended by adding the following proviso
immediately prior to the end thereof:

         "provided, however, the amount of any Person's obligation under any
         Completion Guaranty shall be deemed to be zero unless and until the
         Borrower or any Guarantor shall have recorded the existence of such
         Completion Guaranty as a liability on its financial statement in
         accordance with GAAP."

         (c) The definition of the term "Expansion Capital Expenditure" in
Section 1.1 of the Credit Agreement is hereby amended and restated to read in
its entirety as follows:

                  "Expansion Capital Expenditure" means any Capital Expenditure
         of the Borrower or any of its Subsidiaries which does not relate to the
         Big Red Project (a) made in connection with the Acquisition or
         construction of any Inn that is, or after giving effect to such
         expenditure will be, wholly-owned by the Borrower or a Guarantor or (b)
         which substantially alters, improves or expands any existing Inn, or
         (c) incurred in the ordinary course of business for property used in
         corporate overhead functions, or (d) consisting of land to be leased to
         franchisees, or (e) consisting of a contribution to, or Investment in,
         a Joint Venture, and which in any of the foregoing instances is not
         properly characterized as a Maintenance Capital Expenditure.

         (d) The definition of the term "Inn" in Section 1.1 of the Credit
Agreement is hereby amended and restated to read in its entirety as follows:

                  "Inn" means (i) a Red Roof Inn hotel that is owned by the
         Borrower or a Guarantor or a Joint Venture in which Borrower has made
         an Investment permitted pursuant to Section 7.2.5, or is leased and
         operated by the Borrower or a Guarantor, (ii) the Trueman Club in
         Columbus, Ohio and (iii) a hotel other than a Red Roof Inn that is
         owned by the

                                       -2-
<PAGE>   3
         Borrower or a Guarantor or leased and operated by the Borrower or a
         Guarantor, provided that the total number of Inns described in this
         clause (iii) shall not exceed (except, in the case of acquired hotels,
         for a transitional period not to exceed six months) at any time more
         than 10% of all Inns.

         (e) The definition of the term "Property" in Section 1.1 of the Credit
Agreement is hereby amended and restated to read in its entirety as follows:

                  "Property" means an Inn that is owned in fee or ground-leased
         by the Borrower or a Guarantor or a Joint Venture in which Borrower has
         made an Investment permitted pursuant to Section 7.2.5.

         (f) The definition of the term "Senior EBITDA" in Section 1.1 of the
Credit Agreement is hereby amended and restated to read in its entirety as
follows:

                  "Senior EBITDA" means, for any period, operating income
         (before royalty expenses) from those Properties owned by the Borrower
         or a Guarantor that are not subject to any Liens securing borrowed
         money (other than the Mortgages) or the subject of a sale-leaseback
         transaction (each a "Specified Property") plus (without duplication)
         that portion of any management fees and franchise fees attributable to
         royalty payments, marketing fees, reservation fees, technical fees and
         other similar payments (other than initial franchise fees) received by
         the Borrower or any Subsidiary during such period plus (without
         duplication) rent received by the Borrower or any of its Subsidiaries
         pursuant to the lease of any Specified Property or portion thereof plus
         (without duplication) for any such Inn that shall have been acquired by
         the Borrower during such period, the New Property EBITDA from such Inn
         during such period plus (without duplication) the amount of cash
         distributions received by the Borrower or any Subsidiary from any Joint
         Ventures during such period.

         (g) The definition of the term "Total Debt" in Section 1.1 of the
Credit Agreement is hereby amended and restated to read in its entirety as
follows:

                  "Total Debt" means, as of the last day of any Fiscal Quarter,
         (i) the consolidated Indebtedness (without duplication) of the Borrower
         and its Subsidiaries of the nature referred to in clauses (a)
         (exclusive of unsecured Indebtedness of the Borrower owed to an
         insurance underwriter or related entity to finance payment, and to
         limit the amount, of certain insurance premiums); (b) (exclusive of (I)
         letters of credit issued for the account of the Borrower or any of its
         Subsidiaries in the ordinary course of business to support workers
         compensation and

                                       -3-
<PAGE>   4
         insurance obligations of the Borrower and its Subsidiaries and (II)
         letters of credit (which are not Letters of Credit) issued for the
         account of the Borrower or any of its Subsidiaries); (c); (e); and (f)
         (but only to the extent that the underlying obligations of the type
         referred to above) of the definition of "Indebtedness" plus (ii) seven
         times the Leaseback Rental Payments for such Fiscal Quarter minus (iii)
         cash and cash equivalents of the Borrower and the Guarantors in excess
         of $5,000,000.

         (h) Clause (c) of Section 7.2.2 of the Credit Agreement is hereby
amended by deleting the proviso at the end thereof.

         (i) Clause (f) of Section 7.2.2 of the Credit Agreement is hereby
amended by and restated to read in its entirety as follows:

         "up to $7,000,000 of unsecured Indebtedness of the Borrower or its
         Subsidiaries owed to an insurance underwriter or related entity to
         finance payment and to limit the amount of certain insurance premiums,
         and other unsecured Indebtedness of the Borrower and its Subsidiaries
         (including, without limitation, guarantees by the Borrower of
         Indebtedness of franchisees) in an aggregate amount not to exceed
         $20,000,000 at any time;"

         (j) Clause (d) of Section 7.2.5 of the Credit Agreement is hereby
amended and restated to read in its entirety as follows:

                  "(d) without duplication, Investments permitted as
         Capital Expenditures or Investments in Joint Ventures
         pursuant to Section 7.2.7;"

         (k) Clause (h) of Section 7.2.5 of the Credit Agreement is hereby
amended and restated to read in its entirety as follows:

                  "(h) guarantees of debt incurred by Red Roof Inns franchisees
         as permitted in Section 7.2.2(f); plus other Investments in an
         aggregate amount at any one time not to exceed $30,000,000; provided
         that the aggregate Investments in any franchisee entity, other than
         Investments pursuant to Section 7.2.5(g) and guarantees pursuant to
         Section 7.2.2(f), shall not exceed $2,000,000."

         (l) The proviso at the end of clause (a) of Section 7.2.6 of the Credit
Agreement is hereby amended and restated to read in its entirety as follows:

         "provided, however, that so long as no Specified Default has occurred
         and is continuing or would occur after giving effect thereto, the
         Borrower may (i) pay dividends or distributions on its capital stock
         and

                                       -4-
<PAGE>   5
         warrants or options to purchase its capital stock so long as the
         aggregate amount of dividends and distributions paid in any Fiscal Year
         does not exceed $10,000,000 (provided, however, that up to $2,000,000
         of the unused portion of such allowance for any Fiscal Year may be
         carried forward by the Borrower for one year and provided, further that
         any such amount so carried forward shall be deemed utilized after the
         allowance specifically designated for such Fiscal Year has been
         utilized), (ii) pay current dividends on any Preferred Stock in an
         amount required to be paid under the terms of such Preferred Stock and
         (iii) redeem, purchase or retire shares of its capital stock and
         warrants or options to purchase its capital stock so long as the
         aggregate consideration therefore does not exceed $75,000,000 during
         the remaining term of this Agreement or $50,000,000 from the effective
         date of that certain First Amendment to Credit Agreement dated as of
         December 14, 1998 among the parties hereto through December 31, 1999."

         (m) Clause (b) of Section 7.2.7 of the Credit Agreement is hereby
amended and restated in its entirety to read as follows:

                  "(b) Expansion Capital Expenditures for the Borrower, the
         Guarantors, and, prior to becoming a Guarantor, Carousel shall not
         exceed $120,000,000 in any Fiscal Year; Expansion Capital Expenditures
         consisting of contributions to, or Investments in Joint Ventures shall
         not exceed $20,000,000 in any Fiscal Year; no Expansion Capital
         Expenditure made in respect of any Acquisition shall exceed
         $50,000,000; and no Expansion Capital Expenditure of the type described
         in clause (d) of the definition thereof shall exceed $30,000,000 in any
         Fiscal Year; provided, however, that up to $25,000,000 of the unused
         portion of the scheduled allowance for Expansion Capital Expenditures
         in any Fiscal Year may be carried forward for one year (but no unused
         portion of the allowance for contributions to, or Investments in, Joint
         Ventures may be carried forward); provided, further that any such
         amount so carried forward shall be deemed to be utilized after the
         allowance specifically designated for such Fiscal Year has been fully
         utilized; and provided, however that any acquisitions that are funded
         solely with shares of the Borrower's capital stock shall be excluded
         from such calculations."

         (n) Clause (c) of Section 7.2.10 of the Credit Agreement is hereby
amended by deleting the figure "$50,000,000" and replacing it with the figure
"$100,000,000".

                                       -5-
<PAGE>   6
         2. Effective Date.  This Amendment shall be effective on the date this
Amendment shall have been executed by the Borrower and the Required Lenders.

         3. Representations and Warranties. The Borrower hereby represents and
warrants to the Agent and the Lenders as follows:

                  (a) The Borrower has the power and authority and the legal
right to execute, deliver and perform this Amendment and has taken all necessary
action to authorize the execution, delivery and performance of this Amendment.
This Amendment has been duly executed and delivered by the Borrower. The Credit
Agreement (as amended by this Amendment) and the other Loan Documents constitute
legal, valid, and binding obligations of the Borrower, enforceable against the
Borrower in accordance with their terms, subject to applicable bankruptcy,
insolvency, reorganization, moratorium and other similar laws now or hereafter
in effect relating to creditors' rights generally, and general principles of
equity.

                  (b) At and as of the date of execution hereof and at and as of
the effective date of this Amendment and after giving effect to this Amendment:
(1) the representations and warranties of the Borrower contained in the Credit
Agreement are true and correct in all material respects provided, however, that
with respect to the representations and warranties set forth in Section 6.14 of
the Agreement, the Borrower and the Lenders acknowledge that the Borrower, in
good faith, is in the process of diligently contesting certain proposed income
tax liabilities, as more fully described on Attachment 1, attached to this
Amendment and incorporated herein by this reference; and (2) no Default or Event
of Default has occurred and is continuing under the Credit Agreement.

         4. Reaffirmation of Credit Agreement. This Amendment shall be deemed to
be an amendment to the Credit Agreement, and the Credit Agreement, as amended
hereby, is hereby ratified, approved and confirmed in each and every respect.
All references to the Credit Agreement in any other document, instrument,
agreement or writing shall hereafter be deemed to refer to the Credit Agreement
as amended hereby.

         5. Reaffirmation of Loan Documents. The Borrower hereby further affirms
and agrees that (a) the execution and delivery by the Borrower of and the
performance of its obligations under the Credit Agreement, as amended by this
Amendment, shall not in any way amend, impair, invalidate or otherwise affect
any of the obligations of the Borrower or the rights of the Agent or the Lenders
under any of the Loan Documents or any other document or instrument made or
given by the Borrower in connection therewith, and (b) the term "Obligations" as
used in the Loan Documents includes, without limitation, the Obligations of the
Borrower under the Credit Agreement as amended by this Amendment.

                                       -6-
<PAGE>   7
         6. Miscellaneous Provisions.

                  (a) Survival. The provisions of this Amendment shall survive
any termination of the Credit Agreement, the payment in full of all Obligations
and the termination of all Commitments.

                  (b) Governing Law. THIS AMENDMENT SHALL BE GOVERNED BY AND
CONSTRUED IN ACCORDANCE WITH THE INTERNAL LAWS OF NEW YORK.

                  (c) Counterparts. This Amendment may be executed in any number
of counterparts, all of which together shall constitute one agreement.

                  (d) No Other Amendment. Except as expressly amended herein,
the Credit Agreement, the other Loan Documents and all documents, instruments
and agreements relating thereto or executed in connection therewith shall remain
in full force and effect as currently written.

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

                                            RED ROOF INNS, INC.


                                            By: /s/ David L. Rea
                                               --------------------------------
                                               Title: Executive Vice President,
                                               Chief Financial Officer and 
                                               Treasurer


                                            CIBC OPPENHEIMER CORP.,
                                               as Syndication and Documentation
                                               Agent, and Arranger


                                            By: /s/ Paul J. Chakmak
                                               --------------------------------
                                               Title: Managing Director


                                            THE HUNTINGTON NATIONAL BANK,
                                             as Collateral Agent,
                                               Administrative Agent and Arranger


                                            By: /s/ Robert H. Friend
                                               --------------------------------
                                               Title: Vice President


                                       -7-
<PAGE>   8
                                                        LENDERS
                                                        -------

                                            CIBC INC.

                                            By: /s/ Paul J. Chakmak
                                               --------------------------------
                                               Title: Managing Director
                                               CIBC Oppenheimer Corp.,
                                               AS AGENT


                                            THE HUNTINGTON NATIONAL BANK


                                            By: /s/ Robert H. Friend
                                               --------------------------------
                                               Title: Vice President


                                            BANK ONE, NA


                                            By: /s/ Rebecca McCloskey
                                               --------------------------------
                                               Title: First Vice President


                                            PNC BANK, NATIONAL ASSOCIATION


                                            By: /s/ Wayne Robertson
                                               --------------------------------
                                               Title: Vice President


                                            BANQUE NATIONALE DE PARIS


                                            By: /s/ Arnaud Collin du Bocage
                                               --------------------------------
                                               Title: Executive Vice President
                                               & General Manager


                                            NBD BANK, A MICHIGAN BANKING
                                            CORPORATION


                                            By: /s/ Rebecca McCloskey
                                               --------------------------------
                                               Title: First Vice President


                                            HARRIS TRUST AND SAVINGS BANK


                                            By: /s/ W.A. McDonnell
                                               --------------------------------
                                               Title: Vice President

<PAGE>   9
                                            BANK OF SCOTLAND


                                            By: /s/ Annie Chin Tat
                                               --------------------------------
                                               Title: Senior Vice President


                                            THE FIFTH THIRD BANK OF COLUMBUS


                                            By: /s/ Mark Ransom
                                               --------------------------------
                                               Title: Vice President


                                            NORWEST BANK MINNESOTA, N.A.


                                            By: /s/ R. Duncan Sinclair
                                               --------------------------------
                                               Title: Vice President


                                            STAR BANK, NA


                                            By: /s/ Bonnie Birath
                                               --------------------------------
                                               Title: Assistant Vice President


                                            SUNTRUST BANK, CENTRAL FLORIDA, 
                                            NATIONAL ASSOCIATION


                                            By: /s/ Stephen L. Leister
                                               --------------------------------
                                               Title: Vice President

<PAGE>   10
                                  Attachment 1
                                  ------------



The Internal Revenue Service ("IRS") is currently undergoing an examination of
the Company's federal income tax returns for the years 1993 through 1996. The
IRS has proposed adjustments involving approximately $10 million in current
federal income taxes for the years 1993 through 1997, plus interest. The
proposed adjustments relate primarily to the allocation of the purchase price of
the assets acquired as a result of the merger of the Company in December 1993
and the tax accounting treatment for removal costs for assets replaced. These
adjustments do not affect the overall tax liability recognized by the Company
but only impact the classification between current and deferred tax accounts.
The Company has filed a response vigorously contesting the majority of the
proposed adjustments. While it is not possible to determine the final
disposition, the Company is of the opinion that the ultimate resolution of this
matter should not have a Material Adverse Effect on the financial position or
results of operations of the Company.