<PAGE>
 
                                                                   EXHIBIT 10.12
                              SHAREHOLDERS AGREEMENT
                              ----------------------

     This SHAREHOLDERS AGREEMENT ("Agreement") is dated as of June 29, 1998, by
and among Samstock, L.L.C., a Delaware limited liability company ("Investor"),
David R. Hill, an individual residing in the State of Illinois ("Shareholder"),
and, solely for purposes of Sections 2(a), 2(b), 3, 4, 6 and 8 through 19 of
this Agreement, Davel Communications Group, Inc., an Illinois corporation (the
"Company").

                              W I T N E S S E T H
                              - - - - - - - - - -

     WHEREAS, Investor and the Company are parties to a Stock Purchase Agreement
dated May 14, 1998 (the "Company Stock Purchase Agreement") pursuant to which,
among other things, the Company has agreed to issue and sell, and Investor has
agreed to purchase from the Company, 1,000,000 shares of common stock, no par
value, of the Company ("Common Stock");

     WHEREAS, Investor and Shareholder are parties to a Stock Purchase Agreement
dated May 14, 1998 (the "Shareholder Stock Purchase Agreement") pursuant to
which, among other things, Shareholder has agreed to sell, and Investor has
agreed to purchase from Shareholder, 500,000 shares of Common Stock;

     WHEREAS, Investor and certain directors and members of management of the
Company (the "Management Shareholders") are parties to a Stock Purchase
Agreement pursuant to which, among other things, the Management Shareholders
have agreed to sell, and Investor has agreed to purchase from the Management
Shareholders, 123,900 shares of Common Stock (such Stock Purchase Agreement,
together with the Company Stock Purchase Agreement and the Shareholder Stock
Purchase Agreement, the "Stock Purchase Agreements");

     WHEREAS, the closing of the transactions contemplated by each of the Stock
Purchase Agreements is occurring concurrently with the execution and delivery of
this Agreement;

     WHEREAS, it is a condition to the obligations of Investor to effect the
transactions contemplated by the Company Stock Purchase Agreement that this
Agreement be executed and delivered by Investor and Shareholder;

     WHEREAS, giving effect to the closing of the transactions contemplated by
each of the Stock Purchase Agreements, each of Investor and Shareholder
beneficially owns the number of shares of Common Stock, and options to purchase
shares of Common Stock, set forth opposite its name on Exhibit A hereto; and
                                       
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     WHEREAS, capitalized terms used and not otherwise defined herein shall have
the meanings assigned thereto in the Investment Agreement.

     NOW, THEREFORE, in consideration of the representations, warranties,
covenants and agreements contained in this Agreement, the parties agree as
follows: Section 1. Certain Definitions. 8.Certain Definitions Section
8.Certain Definitions.

     "Affiliate" means, with respect to any Person, any other Person that
directly, or indirectly through one or more intermediaries, controls or is
controlled by or is under common control with such first Person. As used in this
definition "control" (including, with correlative meanings, "controlled by" and
"under common control with") shall mean the possession, directly or indirectly,
of the power to direct or cause the direction of management or policies, whether
through the ownership of securities or partnership or other ownership interests,
by contract or otherwise.

     "business day" means any day that is not a Saturday, a Sunday or a legal
holiday on which banking institutions in the State of Illinois are not required
to be open.

     "Investment Agreement" means the Investment Agreement dated as of the date
hereof among the Company, Investor and Shareholder.

     "Market Price" means the average of the closing prices of the Common Stock
on the Nasdaq Stock Market (or, if not trading on the Nasdaq Stock Market, such
other securities exchange or over the counter market on which the Common Stock
is then trading) on the 20 consecutive Trading Days immediately preceding the
date of determination.

     "Permitted Transferee" means:
      --------------------        
          (i) with respect to the Transfer of Shares by Investor, any person
     that is an Affiliate of Samuel Zell or an Affiliate of any one or more
     trusts established for the benefit of Samuel Zell and/or members of his
     family; and

          (ii) with respect to any Transfer of Shares by Shareholder, (A) any
     Shareholder Family Entity, (B) any charitable organization as defined under
     Section 501(c)(3) of the Internal revenue Code of 1986, as amended, and (C)
     any other charitable organization(s), provided Shareholder does not
     Transfer to any such other charitable organization(s) in the aggregate over
     the term of this Agreement more than ten percent (10%) of the Shares in any
     single Transfer or series (related or unrelated) of Transfers.

     "Person" means any individual, corporation, partnership, limited liability
company, joint venture, governmental entity or other entity.

     "Public Sale" means a bona fide sale of Shares either (i) in "broker's
transactions" within the meaning of Section 4(4) of the Securities Act of 1933,
as amended (the "Securities Act"), (ii) in transactions directly with a "market
maker" as that term in defined in Section 3(a)(38) of the Securities Exchange
Act of 1934, as amended,

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<PAGE>
 
(iii) otherwise pursuant to Rule 144 of the Securities Act, or (iv) through a
registered offering pursuant to an effective registration statement under the
Securities Act.

     "Shares" means all shares of Company Voting Securities, whether now owned
or hereafter acquired.

     "Shareholder Family Entity" means Shareholder's spouse and descendants and
any corporation, partnership, limited liability company, trust, or other legal
entity controlled by Shareholder and wholly owned beneficially and of record by
Shareholder and/or Shareholder's spouse, children, grandchildren, parents,
siblings, in-laws, nieces and/or nephews or a trust established for any of their
benefit, provided such trust is controlled by Shareholder or Shareholder's
representative, or principal heir or legatee.

     "Trading Day" means any day on which the Nasdaq Stock Market is open for
trading.

     "Transfer" means any voluntary or involuntary, direct or indirect,
transfer, sale, assignment, donation, pledge, hypothecation, issuance, grant of
a security interest in or other disposition or attempted disposition of Shares
or any right or interest whatsoever therein, including, without limitation, by
operation of law or otherwise, whether with or without consideration or value,
and whether for cash, other securities or other property and specifically
including any share for share or similar exchange; provided, however, that:

          (i) any pledge or hypothecation of or grant of security interest in
     Shares by Shareholder which is either approved by Investor in writing prior
     to the pledge, hypothecation or grant of security interest or is effected
     by Investor or any Affiliate of Investor shall not constitute a "Transfer"
     of Shares for any purpose under this Agreement; and

          (ii) any Transfer effected as a result of Shareholder's death,
     pursuant to the laws of descent and distribution, by operation of law or
     otherwise, to Shareholder's spouse, children, grandchildren, parents,
     siblings, in-laws, nieces and/or nephews or a trust established for any of
     their benefit, shall not constitute a "Transfer" of Shares for any purpose
     under this Agreement, provided each transferee of Shares executes a
     counterpart to this Agreement, whereupon such transferee shall hold such
     Shares subject to all of the provisions of this Agreement, as if the
     transferor were the holder of Shares held by the transferee.

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     Section 2.  Restrictions on Transfer and Related Matters / Permitted
                 Transferees

          (a) Neither Investor nor Shareholder shall Transfer any Shares except
for a Transfer to a Permitted Transferee pursuant to Section 2(b) or, subject to
Section 6, a Transfer pursuant to Section 3, 4, or 5, as applicable, or pursuant
to the exercise of registration rights under Section 5.3 of the Investment
Agreement. If any Transfer is made or attempted contrary to the provisions of
this Agreement, such purported Transfer shall be void ab initio; and the Company
shall refuse to recognize any such purported transferee of Shares as a holder of
such Shares for any purpose. Notwithstanding anything to the contrary in this
Agreement, the rights of Investor and Shareholder to acquire any Shares pursuant
to their respective rights in Section 3 and 4 shall be subject to compliance
with their respective obligations under Article III of the Investment Agreement.

          (b) Notwithstanding anything to the contrary in Section 2(a) hereof,
for purposes of this Agreement, Shareholder and Investor may Transfer Shares to
a Permitted Transferee of Shareholder and Investor, respectively, without
complying with the provisions of Sections 3, 4, 5 or 6. As a condition to the
effectiveness of any Transfer of Shares to a Permitted Transferee, the Permitted
Transferee shall execute a counterpart to this Agreement, whereupon the
Permitted Transferee shall hold Shares subject to all of the provisions of this
Agreement, as if the Permitted Transferee was the Person who transferred the
Shares actually held by the Permitted Transferee.

     Section 3. Right of First Offer on Private Transfer. In the event either
Shareholder or Investor (in either case, the "Offeror") wishes to sell for cash
in a bona fide transaction with an independent third party, whether or not any
third party has made an offer to purchase any of the Offeror's Shares, all or
any portion of the Shares now owned or hereafter acquired by the Offeror, other
than in a Public Sale, the Offeror shall first notify Investor or Shareholder,
as the case may be (in either case, the "Offeree") and the Company in writing
(the "Notice of Intended Sale") of the number of Shares for sale by the Offeror
(the "Offered Shares") and the terms of sale other than the purchase price. The
Offeree shall promptly engage in discussions with the Offeror, for a period not
to exceed ten (10) business days from the date of receipt by the Offeree and the
Company of the Notice of Intended Sale, to mutually agree on a purchase price
for the Offered Shares. No later than the end of such ten (10) business day
period, the Offeree shall notify the Offeror in writing of the price the Offeree
proposes to pay for all, but not less than all, of the Offered Shares (the
"Offeree Proposed Price"). Within two (2) business days of the receipt of notice
of the Offeree Proposed Price, the Offeror shall notify the Offeree in writing
whether it or he will sell the Offered Shares to the Offeree at the Offeree
Proposed Price in cash and on the other proposed terms of sale. If, within three
(3) business days of receipt by the Offeree and the Company of the Notice of
Intended Sale, the Offeree notifies the Offeror and the Company that it or he
does not wish to purchase the Offered Shares, then the Company shall promptly
(i) notify the Offeror that it does not wish to purchase the Offered Shares, or
(ii) engage in discussions with the Offeror, for a period not to exceed ten (10)
business days from the date of receipt of such notice from the Offeree, to
mutually agree on a purchase price for the Offered Shares. No later than the end
of such ten (10) business day period, the Company shall notify the Offeror in

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<PAGE>
 
writing of the price the Company proposes to pay for all, but not less than all,
of the Offered Shares (the "Company Proposed Price"). Within two (2) business
days of the receipt of notice of the Company Proposed Price, the Offeror shall
have the right to notify the Company in writing whether it or he will sell the
Offered Shares to the Company at the Company Proposed Price in cash and on the
other proposed terms of sale. If the Company notifies the Offeror that it does
not wish to purchase the Offered Shares or if the Company does wish to purchase
the Offered Shares, and the Offeror does not wish to sell all (and not less than
all) of the Offered Shares to the Company at the Company Offered Price, the
Offeror shall be free for a period of ninety (90) days thereafter to complete a
sale of all (but not less than all) of the Offered Shares to any Person at a
price that exceeds either the Offeree Proposed Price or the Company Proposed
Price, as the case may be, if any, in cash and on substantially the same terms
as set forth in the Offeror's Notice of Intended Sale. If such a sale is not
consummated within such ninety (90) day period by the Offeror, the Offered
Shares shall again be subject to a right of first offer by the Offeree and the
Company under the provisions of this Section 3. Except as provided herein,
Investor and Shareholder shall be bound by the restrictions and limitations
imposed by this Agreement after any Notice of Intended Sale is given and whether
or not any sale pursuant thereto actually occurs. In the event any Offeree
exercises its or his rights to purchase shares of Common Stock pursuant to any
Notice of Intended Sale, the Offeree and the Offeror shall, as promptly as
practicable and as a condition to their respective obligations hereunder, enter
into such agreements and deliver such documents to one another as shall be
necessary for the sale of Shares as contemplated hereby.

     Section 4. Right of First Offer on Public Sale. In the event that either
Investor or Shareholder (in either case, the "Offeror") wishes to sell for cash
in a Public Sale all or any portion of the Shares now owned or hereafter
acquired by the Offeror, whether or not any third party has made an offer to
purchase any of the Offeror's Shares, the Offeror shall first notify Investor or
Shareholder, as the case may be (the "Offeree"), and the Company in writing (the
"Notice of Intended Sale") of the number of Shares for sale by the Offeror (the
"Offered Shares"). The Offeree thereupon shall have the right to purchase all or
any part of the Offered Shares for cash at their Market Price determined as of
the last Trading Day immediately prior to the date of the Offeree's receipt of
the Notice of Intended Sale. In order to exercise the purchase rights, within
three (3) business days (one (1) business day in the event of a proposed Public
Sale of no more than 10,000 Shares in the aggregate) after receiving the Notice
of Intended Sale from the Offeror, the Offeree shall deliver to the Offeror and
the Company a written election ("Election Notice") to purchase so many of the
Offered Shares as it or he may desire to purchase. If the Offeree does not
exercise the purchase rights with respect to all of the Offered Shares within
the time period as provided herein or fails to deliver the Election Notice
within the time period provided, the Company shall have the right to purchase
all (but not less than all) of the Offered Shares at the proposed price in cash
and on the other proposed terms of sale. In order to exercise its purchase
rights, within three (3) business days (one (1) business day in the event of a
proposed sale of no more than 10,000 Shares

                                       5
<PAGE>
 
in the aggregate) after the expiration of the time period applicable to the
Offeree, the Company shall deliver to the Offeror a written election (the
"Election Notice") to purchase all of the Offered Shares. If the Company does
not exercise its purchase rights with respect to all (and not less than all) of
the Offered Shares within the time period as provided herein with respect to all
of the Offered Shares, or fails to deliver the Election Notice within the time
period provided, the Offeror shall be free for a period of twenty (20) Trading
Days thereafter to complete a Public Sale of that number of Offered Shares with
respect to which the Offeree and the Company failed to exercise their purchase
rights. If such Public Sale is not consummated within such twenty (20) Trading
Day period by the Offeror, the Offered Shares shall again be subject to a right
of first offer by the Offeree and the Company under the provisions of this
Section 4. Except as provided herein, Investor and Shareholder shall be bound by
the restrictions and limitations imposed by this Agreement after any Notice of
Intended Sale is given and whether or not any sale pursuant thereto actually
occurs. In the event any Offeree exercises its or his rights to purchase shares
of Common Stock pursuant to any Notice of Intended Sale, the Offeree and the
Offeror shall, as promptly as practicable and as a condition to their respective
obligations hereunder, enter into such agreements and deliver such documents to
one another as shall be necessary for the sale of Shares as contemplated hereby.
Notwithstanding anything to the contrary in this Section 4, in the event that
after the Offeree's receipt of the Notice of Intended Sale and prior to the
earlier of (i) the Offeror's receipt of the Election Notice or (ii) 5:00 p.m.
Eastern Time on the fourth (4th) day following the Offeree's receipt of the
Notice of Intended Sale, the Market Price of the Shares increases or decreases
by ten percent (10%) or more as compared to the Market Price on the last Trading
Day immediately prior to the date of the Offeree's receipt of the Notice of
Intended Sale, the Offeror shall have the right to withdraw its Notice of
Intended Sale by written notice to the Offeree and the Company, in which event
the Notice of Intended Sale actually delivered by the Offeror to the Offeree and
the Company shall be deemed for all purposes under this Section 4 as never
having been delivered to the Offeree and the Company.

     Section 5. Co-Sale Rights. In addition to the rights of Investor,
Shareholder and the Company set forth in Section 3 above, in the event that
either Investor or Shareholder (in either case, the "Selling Holder") enters
into an agreement to sell to any person other than a Permitted Transferee (and
other than with the Company pursuant to Section 3 or Section 4) or group of any
such persons, in a single transaction or related series of transactions, other
than a Public Sale, such number of Shares as equals or exceeds more than ten
percent (10%) of the Shares held by the Selling Holder as of the date hereof
(giving effect to the closing of the transactions contemplated by the Stock
Purchase Agreements), the Selling Holder shall first notify Investor or
Shareholder, as the case may be (the "Tag-Along Holder"), in writing, of the
identity of the proposed purchaser(s), the number of Shares proposed to be sold,
the proposed purchase price and terms of sale and an estimate of the Transaction
Costs (as defined below) (which estimate shall be a reasonably determined
estimate but otherwise shall not be binding on the Selling Holder and shall have
no effect on Investor's or Shareholder's rights or obligations under this
Section 5). The Tag-Along Holder thereupon shall have the right to participate
in the proposed sale at the same net price per share and other terms and
conditions of sale as offered to the Selling Holder. In order to exercise the 
co-sale rights,

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<PAGE>
 
the Tag-Along Holder, within ten (10) business days after receiving notice from
the Selling Holder, shall deliver to the Selling Holder a written election to
participate in the sale to the extent allowed by this Section 5. If the Tag-
Along Holder has elected to participate in the proposed sale, the Tag-Along
Holder shall be entitled to sell in the proposed sale a number of Shares equal
to the product of (i) the quotient (the "Co-Sale Fraction") determined by
dividing the number of Shares owned by the Tag-Along Holder by the aggregate
number of Shares owned by the Selling Holder and the Tag-Along Holder multiplied
by (ii) the total number of Shares to be sold by them in the proposed sale.
Notwithstanding anything to the contrary in this Section 5, the sale proceeds to
which the Tag-Along Holder would otherwise be entitled by reason of its or his
participation in a sale pursuant to this Section 5 shall be reduced by an amount
equal to the product of the Tag-Along Holder's Co-Sale Fraction multiplied by
the sum of any costs, fees and expenses, including, without limitation,
attorneys', accountants' and investment bankers' fees and expenses
(collectively, "Transaction Costs"), reasonably incurred by the Selling Holder
in connection with the sale or the exercise of the Tag-Along Holder's rights
under this Section 5. The Tag-Along Holder shall, as promptly as practicable and
as a condition to its or his participation, enter into such agreements as shall
be reasonably requested by the Selling Holder for the sale of its or his Shares
in the proposed sale; provided that the Selling Holder shall use reasonable
efforts to negotiate indemnities on a several, and not joint, basis, and that in
all events any indemnity by the Tag-Along Holder will be limited to the net
proceeds received by the Tag-Along Holder (it being understood that if either or
both of these points are not successfully negotiated, the Tag-Along Holder may
withdraw its notice of its election to participate in the sale).

     Section 6. Transfers of Company Voting Securities. (a) Except as the same
may be approved by a majority of the Disinterested Directors in a specific
resolution to such effect adopted prior to the taking of such action, no member
of the Investor Group shall, directly or indirectly, sell, transfer or otherwise
dispose of any Company Voting Securities to any person or group (other than to
another member of the Investor Group) prior to the third anniversary of the
Effective Date in a transaction that would, to the knowledge of the Investor
Group, upon consummation of such sale, transfer or disposition, result in such
person or group beneficially owning Company Voting Securities that would
represent 5% or more of the Combined Voting Power of all Company Voting
Securities; provided, however, that any member of the Investor Group shall be
entitled to pledge or hypothecate any number of Company Voting Securities to any
bank or other financial institution in connection with any bona fide financing
transaction involving any member of the Investor Group or any of its Affiliates
and, upon any realization of the collateral represented by such pledge or
hypothecation, the pledgee shall take and own such Company Voting Securities
free and clear of, and not subject to any of the restrictions set forth in, this
agreement. Notwithstanding the foregoing, on and after the eleventh business day
following commencement of a tender or exchange offer made by a person who is not
a member of the Investor Group for outstanding Company Voting Securities, any
member of the Investor Group may tender or

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<PAGE>
 
exchange any Company Voting Securities beneficially owned by it pursuant to such
tender or exchange offer if such tender or exchange offer shall have been
approved or recommended by a majority of the Disinterested Directors.

          (b)  Except as the same may be approved by a majority of the
Disinterested Directors in a specific resolution to such effect adopted prior to
the taking of such action, no member of the Shareholder Group shall, directly or
indirectly, sell, transfer or otherwise dispose of any Company Voting Securities
to any person or group (other than to another member of the Shareholder Group)
prior to the third anniversary of the Effective Date in a transaction that
would, to the knowledge of the Shareholder Group, upon consummation of such
sale, transfer or disposition, result in such person or group beneficially
owning Company Voting Securities that would represent 5% or more of the Combined
Voting Power of all Company Voting Securities; provided, however, that any
member of the Shareholder Group shall be entitled to pledge or hypothecate any
number of Company Voting Securities to any bank or other financial institution
in connection with any bona fide financing transaction involving any member of
the Shareholder Group or any of its Affiliates and, upon any realization of the
collateral represented by such pledge or hypothecation, the pledgee shall take
and own such Company Voting Securities free and clear of, and not subject to any
of the restrictions set forth in, this Agreement. Notwithstanding the foregoing,
on and after the eleventh business day following commencement of a tender or
exchange offer made by a person who is not a member of the Shareholder Group for
outstanding Company Voting Securities, any member of the Shareholder Group may
tender or exchange any Company Voting Securities beneficially owned by it
pursuant to such tender or exchange offer if such tender or exchange offer shall
have been approved or recommended by a majority of the Disinterested Directors.

     Section 7. Board Seats. So long as Shareholder is entitled to designate
directors in accordance with the provisions of Section 4.5 of the Investment
Agreement, Investor shall vote all Company Voting Securities owned of record by
Investor or with respect to which Investor has voting control in favor of the
election of Shareholder's nominees to the Company's Board of Directors and the
Independent Director nominees chosen in accordance with the terms of the
Investment Agreement. So long as Investor is entitled to designate directors in
accordance with the provisions of Section 4.4 of the Investment Agreement,
Shareholder shall vote all Company Voting Securities owned of record by
Shareholder or with respect to which Shareholder has voting control in favor of
the election of Investor's nominees to the Company's Board of Directors and the
Independent Director nominees chosen in accordance with the terms of the
Investment Agreement.

     Section 8. Notices. All notices and other communications hereunder shall be
in writing and shall be deemed given if delivered personally, sent by documented
overnight delivery service or, to the extent receipt is confirmed, telecopy, to
the appropriate address or telecopy number set forth below (or at such other
address or telecopy number for a party as shall be specified by like notice):

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<PAGE>
 
               if to Investor:

               Samstock, L.L.C.
               Two N. Riverside Plaza
               Chicago, IL 60606
               Attention: F. Philip Handy
               Telecopy Number: (312) 454-1671

               with a copy to:

               Rosenberg & Liebentritt, P.C.
               Two N. Riverside Plaza
               Chicago, IL 60606
               Attention: Walter S. Lowry
               Telecopy Number: (312) 454-0335

               if to the Company:

               Davel Communications Group, Inc.
               1429 Massaro Boulevard
               Tampa, Florida 33619
               Attention: Robert D. Hill
               Telecopy Number: (813) 626-9610
               with a copy to:

               Kirkland & Ellis
               200 E. Randolph Drive
               Chicago, IL 60601
               Attention: R. Scott Falk
               Telecopy Number: (312) 861-2200

               with an additional copy to:

               Davel Communications Group, Inc.
               1429 Massaro Boulevard
               Tampa, Florida 33619
               Attention: Theodore C. Rammelkamp, Jr.
               Telecopy Number: (813) 626-9610

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<PAGE>
 
               If to Shareholder:

               Mr. David R. Hill
               601 West Morgan
               Jacksonville, IL 62650
               Telecopy Number: (217) 243-6016

     Section 9. Termination. Unless this Agreement specifically provides for
earlier or later termination with respect to any particular right or obligation,
this Agreement shall terminate and be of no further force and effect (i) in the
case of Investor, if Investor and its Permitted Transferees shall, at any time,
cease to own in the aggregate Company Voting Securities representing at least
five percent (5%) of all Company Voting Securities outstanding or (ii) in the
case of Shareholder, if Shareholder and its Permitted Transferees shall, at any
time, cease to own in the aggregate Company Voting Securities representing at
least five percent (5%) of all Company Voting Securities outstanding.

     Section 10. Remedies. Any party having rights under this Agreement may
enforce such rights specifically to recover damages caused by reason of any
breach of any provision of this Agreement and to exercise all other rights
granted by law. The parties agree and acknowledge that money damages may not be
an adequate remedy for any breach of the provisions of this Agreement and,
accordingly, in addition to all other remedies available to any party, such
party may in its sole discretion apply to any court of law or equity of
competent jurisdiction for specific performance and/or injunctive relief in
order to enforce, or prevent any violation of, the provisions of this Agreement.

     Section 11. Entire Agreement. This Agreement (including the documents
referred to herein) (a) constitutes the entire agreement, and supersedes all
prior agreements and understandings, both written and oral, between the parties
with respect to the subject matter of this Agreement and (b) is not intended to
confer upon any Person other than the parties rights or remedies.

     Section 12. Amendments; Waivers. (a) This Agreement may not be modified or
amended except by an instrument or instruments in writing signed by each party
hereto.

               (b) The failure of any party hereto to comply with any
representation, warranty, covenant or agreement contained in this Agreement may
be waived only by a written instrument signed by the party granting such waiver.
No action taken pursuant to this Agreement, including any investigation by or on
behalf of any party, shall be deemed to constitute a waiver by the party taking
such action of compliance with any representation, warranty, covenant or
agreement contained in this Agreement, and no failure by any party to take any
action with respect to any breach of this Agreement or default by any other
party shall constitute a waiver of such party's right to enforce any provision
hereof or to take any such action. The waiver by any party hereto of a breach of
any provision hereunder shall not operate

                                      10
<PAGE>
 
as a waiver of any prior or subsequent breach of the same or any other provision
hereunder.

     Section 13. Counterparts. This Agreement may be executed in two or more
counterparts, all of which shall be considered one and the same Agreement, and
shall become effective when one or more counterparts have been signed by each of
the parties and delivered to the other parties.

     Section 14. Severability. Any provision hereof which is invalid or
unenforceable shall be ineffective to the extent of such invalidity or
unenforceability, without affecting in any way the remaining provisions hereof.

     Section 15. Governing Law. This Agreement shall be governed by, and
construed in accordance with, the laws of the State of Illinois regardless of
the laws that might otherwise govern under applicable principles of conflicts of
law thereof.

     Section 16. Binding Effect; Benefit, Non-circumvention. This Agreement
shall inure to the benefit of and be binding upon the parties hereto, and their
successors and permitted assigns. Nothing in this Agreement, express or implied,
is intended to confer on any Person other than the parties hereto, and their
respective successors and permitted assigns any rights, remedies, obligations or
liabilities under or by reason of this Agreement. No shareholder shall take any
action, alone or in concert with any other Person, to circumvent any of the
provisions of this Agreement.

     Section 17. Assignment. Neither this Agreement nor any of the rights,
interest or obligations under this Agreement shall be assigned, in whole or in
part, by operation of law or otherwise by any of the parties without the prior
written consent of the other parties, except that Investor may assign any of or
all of its rights and obligations under this Agreement to any person that is an
Affiliate of Samuel Zell or an Affiliate of any one or more trusts established
for the benefit of Samuel Zell and/or members of his family without the consent
of any other party, and Shareholder may assign any of or all of his rights and
obligations under this Agreement to one or more Affiliates of Shareholder
(including any Shareholder Family Entity) without the consent of any other
party; provided that, in each case, such person or persons shall have executed
and delivered a joinder to this Agreement and agreed to be bound by the terms
and conditions hereof. Subject to the preceding sentence, this Agreement shall
be binding upon, and inure to the benefit of, the parties hereto and their
respective successors and assigns.

                                      11
<PAGE>
 
     Section 18. Interpretation. The headings contained in this Agreement are
inserted for convenience of reference only and shall not affect in anyway the
meaning or interpretation of this Agreement. All references to a Section,
Article, Schedule or Exhibit contained herein mean Sections, Articles, Schedules
or Exhibits of this Agreement unless otherwise stated. All capitalized terms
defined herein are equally applicable to both the singular and plural forms of
such terms.

     Whenever the words "include", "includes" or "including" are used in this
Agreement, they shall be deemed to be followed by the words "without
limitation".

     Section 19. Consent to Jurisdiction. Each party hereto irrevocably submits
to the nonexclusive jurisdiction of (a) the state courts of the State of
Illinois and (b) any federal district court in the State of Illinois for the
purposes of any suit, action or other proceeding arising out of this Agreement
or any transaction contemplated hereby.

                                      12
<PAGE>
 
     IN WITNESS WHEREOF, the undersigned have executed this Shareholders
Agreement as of the day and year first above written.


                                      SAMSTOCK, L.L.C.



                                      ____________________________________
                                      By:




                                      ____________________________________
                                      David R. Hill, individually




                                           DAVEL COMMUNICATIONS GROUP, INC.



                                           _______________________________
                                           By:

                                       13
<PAGE>
 
                                                                       EXHIBIT A
                                                                       ---------


                 OWNERSHIP OF DAVEL COMMUNICATIONS GROUP, INC.
                           COMMON STOCK AND OPTIONS
                           ------------------------

Investor Shares:





Shareholder Shares:



Shareholder Options Schedule

<TABLE>
<CAPTION>
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
Options Date         Exp. Date      Option Price      Shares         Shares
--------------       ---------      ------------      Outstanding    Exercisable
                                                      -----------    -----------
<S>                  <C>            <C>               <C>            <C>
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
</TABLE>

                                       14