EXHIBIT 25

                      SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C. 20549


                                   --------
                      STATEMENT OF ELIGIBILITY UNDER THE
                       TRUST INDENTURE ACT OF 1939 OF A
                   CORPORATION DESIGNATED TO ACT AS TRUSTEE

               Check if an Application to Determine Eligibility
                 of a Trustee Pursuant to Section 305(b)(2)__

             STATE STREET BANK AND TRUST COMPANY OF MISSOURI, N.A.
              (Exact name of trustee as specified in its charter)

               U.S. national bank                           43-1745664
       (Jurisdiction of incorporation or                 (I.R.S. Employer
    organization if not a U.S. national bank)           Identification No.)

   127 West 10th Street, Kansas City, Missouri                 64105
     (Address of principal executive offices)               (Zip Code)

                          Susan James, Vice President
             State Street Bank and Trust Company of Missouri, N.A.
                        211 North Broadway, Suite 3900
                           St. Louis, Missouri 63102

           (Name, address and telephone number of agent for service)

                                   --------

                         PRIME MEDICAL SERVICES, INC.
              (Exact name of obligor as specified in its charter)

              Delaware                                     74-2652727
    (State or other jurisdiction of                     (I.R.S. Employer
    incorporation or organization)                     Identification No.)

                  1301 Capital of Texas Highway, Suite C-300
                           Austin, Texas  78746-6550
              (Address of principal executive offices) (Zip Code)

                                   --------



                 Senior Subordinated Notes, 8.75% Due 4/1/2008

                        (Title of indenture securities)

 
                                    GENERAL

ITEM 1.   General Information.

          Furnish the following information as to the trustee:

          (a)  Name and address of each examining or supervisory authority to
          which it is subject.

             Comptroller of the Currency of the United States, Washington, D.C.

Item 2.   Affiliations with Obligor.

          If the Obligor is an affiliate of the trustee, describe each such
          affiliation.

          The obligor is not an affiliate of the trustee or of its parent,
          State Street Bank and Trust Company.
               (See note on page 2.)

Item 3. through Item 15. Not applicable.

Item 16.  List of Exhibits.

          List below all exhibits filed as part of this statement of
          eligibility.

          1.   A copy of the articles of association of the trustee as now in
          effect.

               A copy of the articles of association of the Trustee, as now in
          effect, is attached hereto as Exhibit 1 and made a part hereof.

          2.   A copy of the certificate of authority of the trustee to
          commence business, if not contained in the articles of association.

               A copy of the certificate of the Comptroller of the Currently
          authorizing the trustee to commence the business of banking as a
          national banking association is attached hereto as Exhibit 2 and made
          a par hereof.

          3.   A copy of the authorization of the trustee to exercise corporate
          trust powers, if such authorization is not contained in the documents
          specified in paragraph (1) or (2), above.

               A copy of the certificate of the Comptroller of the Currency
          dated September 15, 1995 authorizing the trustee to exercise corporate
          trust powers is attached hereto as Exhibit 3 and made a part hereof.

          4.   A copy of the existing by-laws of the trustee, or instruments
          corresponding thereto.

               A copy of the existing amended and restated by-laws of the
          trustee is attached hereto as Exhibit 4.
                                       1

 
          5.   A copy of each indenture referred to in Item 4. if the obligor is
in default.

                 Not applicable.

          6.   The consents of United States institutional trustees required by
Section 321(b) of the Act.

                 The consent of the trustee required by Section 321(b) of the
Act is annexed hereto as Exhibit 6 and made a part hereof.

          7.   A copy of the latest report of condition of the trustee published
pursuant to law or the requirements of its supervising or examining authority.

                 A copy of the latest report of condition of the trustee
published pursuant to law or the requirements of its supervising or examining
authority is annexed hereto as Exhibit 7 and made a part hereof.



                                     NOTES

          In answering any item of this Statement of Eligibility and
Qualification which relates to matters peculiarly within the knowledge of the
obligor or any underwriter for the obligor, the trustee has relied upon
information furnished to it by the obligor and the underwriters, and the trustee
disclaims responsibility for the accuracy or completeness of such information.

          The answer furnished to Item 2. of this statement will be amended, if
necessary, to reflect any facts which differ from those stated and which would
have been required to be stated if known at the date hereof.


                                   SIGNATURE

          Pursuant to the requirements of the Trust Indenture Act of 1939, as
amended, the trustee, State Street Bank and Trust Company of Missouri N.A., a
national banking association existing under the laws of the United States
of America, has duly caused this statement of eligibility and qualification to
be signed on its behalf by the undersigned, thereunto duly authorized, all in
the City of St. Louis and the State of Missouri, on the 14th day of April, 1998.


                                        STATE STREET BANK AND TRUST COMPANY
                                        OF MISSOURI, N.A.



                                        By: /s/ ROBERT A. CLASQUIN
                                            ------------------------------------
                                            Robert A. Clasquin
                                            Assistant Vice President

 
                                   EXHIBIT 1
                            ARTICLES OF ASSOCIATION
                                      OF
               STATE STREET BANK AND TRUST COMPANY OF MISSOURI,
                             NATIONAL ASSOCIATION

          For the purpose of organizing an Association to carry on the business
of a limited purpose trust company under the laws of the United States, the
undersigned do enter into the following Articles of Association:

          FIRST.    The title of this Association shall be State Street Bank and
Trust Company of Missouri, National Association.

          SECOND.   The Main Office of the Association shall be in the City of
Kansas City, County of Jackson, State of Missouri. The business of the
Association will be limited to the operations of a national trust company and
to support activities incidental thereto. The Association will not expand or
alter its business beyond that stated in this Article Second without the prior
approval of the Comptroller of the Currency.

          THIRD.    The Board of Directors of this Association shall consist of
not less than five nor more than twenty-five shareholders, the exact number to
be fixed and determined from time to time by resolution of a majority of the
full Board of Directors or by resolution of the shareholders at any annual or
special meeting thereof. Each Director, during the full term of his or her
directorship, shall own a minimum of $1,000 aggregate par value of stock of this
Association or a minimum par, market value or equity interest of $1,000 of stock
in the bank holding company controlling this Association.

          Any vacancy in the Board of Directors may be filled by action of the
Board of Directors; provided, however, that a majority of the full Board of
Directors may not increase the number of Directors to a number which: (1)
exceeds by more than two the number of Directors last elected by shareholders
where the number was 15 or less; and (2) exceeds by more than four the number of
Directors last elected by shareholders where the number was 16 or more, but in
no event shall the number of directors exceed 25.

          Terms of Directors, including Directors selected to fill vacancies,
shall expire at the next regular meeting of shareholders at which Directors are
elected, unless the Directors resign or are removed from office. Despite the
expiration of a Director's term, the Director shall continue to serve until his
or her successor is elected and qualifies or until there is a decrease in the
number of Directors and his or her position is eliminated.

          FOURTH.   There shall be an annual meeting of the shareholders to
elect Directors and transact whatever other business may be brought before the
meeting. It shall be held at the main office or any other convenient place as
the Board of Directors may designate, on the day of each year specified
therefore in the By-laws, but if no election is held on that day, it may be held
on any subsequent day according to such lawful rules as may be prescribed by the
Board of Directors.

          Nominations for election to the Board of Directors may be made by the
Board of Directors or by any shareholder of any outstanding class of capital
stock of this Association entitled to vote for election of Directors.
Nominations other than those made by or on behalf of the existing management
shall be made in writing and be delivered or mailed to the president of this
Association and to the Comptroller of the Currency, Washington, D.C., not less
than 14 days nor more than 50 days prior to any meeting of shareholders called
for the election of Directors; provided, however, that if less than 21 days
notice of the meeting is given to the shareholders, such nominations shall be
mailed or delivered to the president of this Association and to the Comptroller
of the Currency not later than the close of business on the seventh day
following the day on which the notice of meeting was mailed. Such notification
shall contain the following information to the extent known to the notifying
shareholder: the name and address of each proposed nominee; the principal
occupation of each proposed nominee; the total number of shares of capital
stock of this Association that will be voted for each proposed nominee; the
name and residence address of the notifying shareholder; and the number of
shares of capital stock of this Association owned by the notifying shareholder.
Nominations not made in accordance herewith may, in his or her discretion, be
disregarded by the chairperson of the meeting, and upon his or her
instructions, the vote tellers may disregard all votes cast for each such
nominee.

 
          FIFTH.    The authorized amount of capital stock of this Association
shall be 1,000,000 shares of common stock of the par value of one dollar ($1)
each; but said capital stock may be increased or decreased from time to time,
in accordance with the provisions of the laws of the United States.

          No holder of shares of the capital stock of any class of this
Association shall have any preemptive or preferential right of subscription to
any shares of any class of stock of this Association, whether now or hereafter
authorized, or to any obligations convertible into stock of this Association,
issued, or sold, nor any right of subscription to any thereof other than such,
if any, as the Board of Directors, in its discretion may from time to time
determine and at such price as the Board of Directors may from time to time fix.

          Transfers of the Association's capital stock are subject to the prior
approval of a federal depository institution regulatory agency. If no other
agency approval is required, the Comptroller of the Currency's approval
shall be obtained prior to the transfers. In such cases where the Comptroller
of the Currency approval is required, the Comptroller of the Currency will
apply the definitions and standards set forth in the Change in Bank Control
Act and the Comptroller of the Currency's implementing regulation
(12 U.S.C. 1817(j) and 12 C.F.R. 5.50) to ownership changes in the Association.

          This Association, at any time and from time to time, may authorize and
issue debt obligations, whether or not subordinated, without the approval of the
shareholders.



                                      -2-

 
          SIXTH.    The Board of Directors shall appoint one of its members
President of this Association, who shall be Chairperson of the Board, unless the
Board appoints another director to be the Chairperson. The Board of Directors
shall have the power to appoint one or more Vice Presidents; and to appoint a
Cashier and such other officers and employees as may be required to transact the
business of this Association.

          The Board of Directors shall have the power to define the duties of
the officers and employees of this Association; to fix the salaries to be paid
to the officers and employees; to dismiss officers and employees; to require
bonds from officers and employees and to fix the penalty thereof; to regulate
the manner in which any increase of the capital of this Association shall be
made; to manage and administer the business and affairs of this Association; to
make all By-laws that it may be lawful for the Board of Directors to make; and
generally to do and perform all acts that it may be legal for a Board of
Directors to do and perform.

          SEVENTH.  The Board of Directors shall have the power to change the
location of the main office to any other place within the limits of the City of
Kansas City, without the approval of the shareholders, and shall have the power
to establish or change the location of any branch or branches of this
Association to any other location, without the approval of the shareholders.

          EIGHTH.   The corporate existence of this Association shall continue
until terminated in accordance with the laws of the United States.

          NINTH.    The Board of Directors of this Association, or any
shareholder owning, in the aggregate, not less than ten percent of the stock of
this Association, may call a special meeting of shareholders at any time.
Unless otherwise provided by the laws of the United States, a notice of the
time, place, and purpose of every annual and special meeting of the
shareholders shall be given by first-class mail, postage prepaid, mailed at
least ten days prior to the date of such meeting to each shareholder of record
at his address as shown upon the books of this Association.

                                     - 3 -

 
          TENTH.    This Association shall to the fullest extent legally
permissible indemnify each person who is or was a director, officer, employee or
other agent of this Association and each person who is or was serving at the
request of this Association as a director, trustee, officer, employee or other
agent of another organization or of any partnership, joint venture, trust,
employee benefit plan or other enterprise or organization against all
liabilities, costs and expenses, including but not limited to amounts paid in
satisfaction of judgments, in settlement or as fines and penalties, and counsel
fees and disbursements, reasonably incurred by him in connection with the
defense or disposition of or otherwise in connection with or resulting from any
action, suit or other proceeding, whether civil, criminal, administrative or
investigative, before any court or administrative or legislative or
investigative body, in which he may be or may have been involved as a party or
otherwise or with which he may be or may have been threatened, while in office
or thereafter, by reason of his being or having been such a director, officer,
employee, agent or trustee, or by reason of any action taken or not taken in any
such capacity, except with respect to any matter as to which he shall have been
finally adjudicated by a court of competent jurisdiction not to have acted in
good faith in the reasonable belief that his action was in the best interests of
the corporation (any person serving another organization in one or more of the
indicated capacities at the request of this Association who shall not have been
adjudicated in any proceeding not to have acted in good faith in the reasonable
belief that his action was in the best interest of such other organization shall
be deemed so to have acted in good faith with respect to the National Trust
Company) or to the extent that such matter relates to service with respect to an
employee benefit plan, in the best interest of the participants or beneficiaries
of such employee benefit plan. Expenses, including but not limited to counsel
fees and disbursements, so incurred by any such person in defending any such
action, suit or proceeding, shall be paid from time to time by this Association
in advance of the final disposition of such action, suit or proceeding upon
receipt of an undertaking by or on behalf of the person indemnified to repay the
amounts so paid if it shall ultimately be determined that indemnification of
such expenses is not authorized hereunder.

          As to any matter disposed of by settlement by any such person,
pursuant to a consent decree or otherwise, no such indemnification either for
the amount of such settlement or for any other expenses shall be provided unless
such settlement shall be approved as in the best interests of the National Trust
Company, after notice that it involves such indemnification, (a) by a vote of a
majority of the disinterested directors then in office (even though the
disinterested directors be less than a quorum), or (b) by any disinterested
person or persons to whom the question may be referred by vote of a majority of
such disinterested directors, or (c) by vote of the holders of a majority of the
outstanding stock at the time entitled to vote for directors, voting as a single
class, exclusive of any stock owned by any interested person, or

                                     - 4 -

 
(d)  by any disinterested person or persons to whom the question may be referred
by vote of the holders of a majority of such stock. No such approval shall
prevent the recovery from any such director, officer, employee, agent or trustee
of any amounts paid to him or on his behalf as indemnification in accordance
with the preceding sentence if such person is subsequently adjudicated by a
court of competent jurisdiction not to have acted in good faith in the
reasonable belief that his action was in the best interests of this Association.
The right of indemnification hereby provided shall not be exclusive of or affect
any other rights to which any director, officer, employee, agent or trustee may
be entitled or which may lawfully be granted to him. As used herein, the terms
"director", "officer", "employee", "agent", and "trustee", include their
respective executors, administrators and other legal representatives, an
"interested" person is one against whom the action, suit or other proceeding in
question or another action, suit or other proceeding on the same or similar
grounds is then or had been pending or threatened, and a "disinterested" person
is a person against whom no such action, suit or other proceeding is then or had
been pending or threatened. By action of the board of directors, notwithstanding
any interest of the directors in such action, this Association may purchase and
maintain insurance, in such amounts as the board of directors may from time to
time deem appropriate, on behalf of any person who is or was a director,
officer, employee or other agent of this Association, or is or was serving at
the request of this Association as a director, trustee, officer, employee or
other agent of another organization or of any partnership, joint venture, trust,
employee benefit plan or other enterprise or organization against any liability
incurred by him in any such capacity, or arising out of his status as such,
whether or not this Association would have the power to indemnify him against
such liability.

          Nothing contained in this Article Tenth shall be construed to (i)
allow the indemnification of or insurance coverage for a director, trustee,
officer, employee or agent of this Association against expenses, penalties or
other payments incurred in an administrative action instituted by an appropriate
bank regulatory agency which results in a final order assessing civil money
penalties or requires the payments of money to the Association, or (ii) exceed
the provisions of Massachusetts General Laws, chapter 156B, section 67, as in
effect from time to time.

          ELEVENTH. These Articles of Association may be amended at any regular
or special meeting of the shareholders by the affirmative vote of the holders of
a majority of the stock of this Association, unless the vote of the holders of a
greater amount of stock is required by law, and in that case by the vote of the
holders of such greater amount.

          TWELFTH.  This Association may be a partner in any business or
enterprise which this Association would have power to conduct by itself.


                                     - 5 -

 
          IN WITNESS WHEREOF, we have hereunto set our hands this 27th day of
April, 1995.


                                        /s/ MARSHALL N. CARTER
                                        ----------------------
                                        Marshall N. Carter

                                        /s/ DAVID A. SPINA
                                        ----------------------
                                        David A. Spina

                                        /s/ A. EDWARD ALLINSON
                                        ----------------------
                                        A. Edward Allinson

                                        /s/ RONALD E. LOGUE
                                        ----------------------
                                        Ronald E. Logue

                                        /s/ JOHN R. TOWERS
                                        ----------------------
                                        John R. Towers



                                     - 6 -

 
                                                                       EXHIBIT 2


            [COMPTROLLER OF THE CURRENCY TREASURY DEPARTMENT LOGO]

                               Washington, D.C.


          WHEREAS, satisfactory evidence has been presented to the Comptroller
of the Currency that STATE STREET BANK AND TRUST COMPANY OF MISSOURI, NATIONAL
ASSOCIATION located in KANSAS CITY State of MISSOURI has complied with all
provisions of the statutes of the United States required to be complied with
before being authorized to commence the business of banking as a National
Banking Association;

          NOW, THEREFORE, I hereby certify that the above-named association is
authorized to commence the business of banking as a National Banking
Association.


                    IN TESTIMONY WHEREOF, witness my signature and seal of
                    office this FIFTEENTH day of SEPTEMBER 1995.

                    /s/ DAVID A. BOMGAARS
                    -----------------------------------------
                    District Administrator
                    Comptroller of the Currency


                               Charter No. 22874

 
                                                                       EXHIBIT 3


[LOGO]

Comptroller of the Currency
Administrator of National Banks
Northeastern District
1114 Avenue of the Americas, Suite 3900
New York, New York 10036


                                 TRUST PERMIT

WHEREAS, STATE STREET BANK AND TRUST COMPANY OF MISSOURI, NATIONAL

ASSOCIATION, located in KANSAS CITY, state of MISSOURI, being a National

Banking Association, organized under the statutes of the United States,

has made application for authority to act as fiduciary;


AND WHEREAS, applicable provisions of the statutes of the United States

authorize the grant of such authority;


NOW THEREFORE, I hereby certify that the said association is authorized to act

in all fiduciary capacities permitted by such statutes.


IN TESTIMONY WHEREOF, witness my signature and seal of Office this 15TH day of

SEPTEMBER, 1995.


CHARTER NO. 22874


                                        /s/ DAVID A. BOMGAARS
                                        ---------------------------------
                                            David A. Bomgaars
                                            District Administrator


**OCC SEAL**

 
                                                                       EXHIBIT 4


               STATE STREET BANK AND TRUST COMPANY OF MISSOURI,
                             NATIONAL ASSOCIATION

                             AMENDED AND RESTATED
                                    BY-LAWS


                                   ARTICLE I

                           Meetings of Shareholders

          Section 1.1 Annual Meeting. The regular annual meeting of the
shareholders to elect directors and transact whatever other business may
properly come before the meeting, shall be held at the Main Office of the
National Trust Company, in the City of Kansas City, State of Missouri or such
other places as the Board of Directors may designate, at 10 o'clock, on the
fourth Wednesday of April of each year. Notice of such meeting shall be mailed,
postage prepaid, at least ten days prior to the date thereof, addressed to each
shareholder at his/her address appearing on the books of the National Trust
Company. If for any cause, an election of directors is not made on that day, the
Board of Directors shall order the election to be held on some subsequent day,
as soon thereafter as practicable, according to the provisions of law; and
notice thereof shall be given in the manner herein provided for the annual
meeting.

          Section 1.2. Special Meetings. Except as otherwise specifically
provided by statute, special meetings of the shareholders may be called for any
purpose at any time by the Board of Directors or by any shareholder owning, in
the aggregate, not less than 10 percent of the stock of the National Trust
Company. Every such special meeting, unless otherwise provided by law, shall be
called by mailing, postage prepaid, not less than ten days prior to the date
fixed for such meeting, to each shareholder at his address appearing on the
books of the National Trust Company a notice stating the purpose of the meeting.

          Section 1.3. Nominations for Director. Nominations for election to the
Board of Directors may be made by the Board of Directors or by any shareholder
of any outstanding class of capital stock of the National Trust Company entitled
to vote for the election of directors. Nominations, other than those made by or
on behalf of the existing management of the National Trust Company, shall be
made in writing and shall be delivered or mailed to the President of the
National Trust Company and to the Comptroller of the Currency, Washington, D.C.,
not less than 14 days nor more than 50 days prior to any meeting of shareholders
called for the election of directors, provided however, that if less than 21
days' notice of the meeting is given to shareholders, such nomination shall be
mailed or delivered to the President of the National Trust Company and to the
Comptroller of the Currency not later than the close of business on the seventh
day following the day on which the notice of meeting was mailed. Such
notification shall contain the following information to the extent known to the
notifying shareholder:



     (a) the name and address of each proposed nominee; (b) the principal
occupation of each proposed nominee; (c) the total number of shares of capital
stock of the National Trust Company that will be voted for each proposed
nominee; (d) the name and residence address of the notifying shareholder; and
(e) the number of shares of capital stock of the National Trust Company owned by
the notifying shareholder.  Nominations not made in accordance herewith may, in
his/her discretion, be disregarded by the Chairperson of the meeting, and upon
his/her instructions, the vote tellers may disregard all votes cast for each
such nominee.

          Section l.4. Proxies. Shareholders may vote at any meeting of the
shareholders by proxies duly authorized in writing, but no officer or employee
of this National Trust Company shall act as proxy. Proxies shall be valid only
for one meeting, to be specified therein, and any adjournments of such meeting.
Proxies shall be dated and shall be filed with the records of the meeting.

          Section 1.5. Quorum. A majority of the outstanding capital stock,
represented in person or by proxy, shall constitute a quorum at any meeting of
shareholders, unless otherwise provided by law; but less than a quorum may
adjourn any meeting, from time to time, and the meeting may be held, as

 
adjourned, without further notice. A majority of the votes cast shall decide
every question or matter submitted to the shareholders at any meeting, unless
otherwise provided by law or by the Articles of Association.


                                  ARTICLE II

                                   Directors

          Section 2.1. Board of Directors. The Board of Directors shall have the
power to manage and administer the business and affairs of the National Trust
Company. Except as expressly limited by law, all corporate powers of the
National Trust Company shall be vested in and may be exercised by the Board of
Directors.

          Section 2.2. Number. the Board of Directors shall consist of not less
than five nor more than twenty-five shareholders, the exact number within such
minimum and maximum limits to be fixed and determined from time to time by
resolution of a majority of the full Board or by resolution of the shareholders
at any meeting thereof.

          Section 2.3. Organization Meeting. The Cashier, upon receiving the
results of any election, shall notify the directors-elect of their election and
of the time at which they are required to meet at the Main Office of the
National Trust Company to organize the new Board and elect and appoint officers
of the National Trust Company for the succeeding year. Such meeting shall be
held on the day of the election or as soon thereafter as practicable, and, in
any event, within thirty days thereof. If, at the time fixed for such meeting,
there shall not be a quorum present, the Directors present may adjourn the
meeting, from time to time, until a quorum is obtained.

                                      -2-

 
          Section 2.4. Regular Meetings. Regular Meetings of the Board of
Directors shall be held, without notice, at least once in each quarter on such
days and at such hours as the Directors may from time to time determine. When
any regular meeting of the Board falls upon a holiday, the meeting shall be held
on the next banking business day unless the Board shall designate some other
day. (Amended 1/1/97)

          Section 2.5. Special Meetings. Special meetings of the Board of
Directors may be called by the Chairman of the Board of the National Trust
Company, or at the request of three or more directors. Each member of the Board
of Directors shall be given notice stating the time and place, by telegram,
letter, or in person, of each such special meeting.

          Section 2.6. Quorum. A majority of the directors shall constitute a
quorum at any meeting, except when otherwise provided by law; but a less number
may adjourn any meeting, from time to time, and the meeting may be held, as
adjourned, without further notice.

          Section 2.7. Vacancies. When any vacancy occurs among the directors,
the remaining members of the Board, in accordance with the laws of the United
States, may appoint a director to fill such vacancy at any regular meeting of
the Board, or at a special meeting called for that purpose in conformance with
Section 2.2 of this Article.

          Section 2.8. Action Without a Meeting. Any action required or
permitted to be taken at any meeting of the Directors may be taken without a
meeting if all the Directors consent to the action in writing and the written
consents are filed with the records of the meetings of the Directors. Such
consents shall be treated for all purposes as a vote at a meeting.

          Section 2.9. Meeting by Telecommunications. Members of the Board of
Directors or any committee elected thereby may participate in a meeting of such
Board or committee by means of a conference telephone or similar communications
equipment by means of which all persons participating in a meeting can hear each
other at the time and participation by such means shall constitute presence in
person at the meeting.

                                  ARTICLE III

                            Committees of the Board

          Section 3.1. Investment Committee. There shall be an Investment
Committee composed of not less than two Directors, appointed by the Board
annually or more often. The Investment Committee shall have the power to insure
adherence to Investment Policy, to recommend amendments thereto, to purchase and
sell securities, to exercise authority regarding investments and to exercise,
when the Board is not in session, all other powers of the Board regarding
investment securities that may be lawfully delegated. The Investment Committee
shall keep minutes of its meetings, and such minutes shall be submitted at the
next regular meeting of the Board of Directors at which a quorum is present, and
any action taken by the Board with respect thereto shall be entered in the
minutes of the Board.

                                      -3-
 

 
          Section 3.2. Examining Committee. There shall be an Examining
Committee composed of not less than two directors, exclusive of any active
officers, appointed by the Board annually or more often, whose duty it shall be
to make an examination at least once during each calendar year into the affairs
of the National Trust Company or cause suitable examinations to be made by
auditors responsible only to the Board of Directors and to report the result of
such examination in writing to the Board at the next regular meeting thereafter.
Such report shall state whether the National Trust Company is in a sound
condition, and whether adequate internal controls and procedures are being
maintained shall recommend to the Board of Directors such changes in the manner
of conducting the affairs of the National Trust Company as shall be deemed
advisable. (Amended 8/5/97)

          Section 3.3. Other Committees. The Board of Directors may appoint,
from time to time, from its own members, other committees of one or more
persons, for such purposes and with such powers as the Board may determine.
However, a committee may not authorize distribution of assets or dividends;
approve action required to be approved by shareholders; fill vacancies on the
board of directors or any of its committees; amend articles of association;
adopt, amend or repeal by-laws; or authorize or approve issuance or sale or
contract for sale of shares, or determine the designation and relative rights,
preferences and limitations of a class or series of shares.

                                  ARTICLE IV

                            Officers and Employees

          Section 4.1. Chairperson of the Board. The Board of Directors shall
appoint one of its members to be Chairperson of the Board to serve at its
pleasure. Such person shall preside at all meetings of the Board of Directors.
The Chairperson of the Board shall supervise the carrying out of the policies
adopted or approved by the Board; shall have general executive powers, as well
as the specific powers conferred by these Bylaws; and shall also have and may
exercise such further powers and duties as from time to time may be conferred
upon, or assigned by the Board of Directors.

          Section 4.2. President. The Board of Directors shall appoint one of
its members to be President of the National Trust Company. In the absence of the
Chairperson, the President shall preside at any meeting of the Board. The
President shall have general executive powers, and shall have and may exercise
any and all other powers and duties pertaining by law, regulations, or practice,
to the Office of President, or imposed by these Bylaws. The President shall also
have and may exercise such further powers and duties as from time to time may be
conferred, or assigned by the Board of Directors.

          Section 4.3. Vice President. The Board of Directors may appoint one or
more Vice Presidents. Each Vice President shall have such powers and duties as
may be assigned by the Board of Directors. One Vice President shall be
designated by the Board of Directors, in the absence of the President, to
perform all the duties of the President.


                                      -4-

 
          Section 4.4. Secretary. The Board of Directors shall appoint a
Secretary, Cashier, or other designated officer who shall be Secretary of the
Board and of the National Trust Company, and shall keep accurate minutes of all
meetings. The Secretary shall attend to the giving of all notices required by
these Bylaws to be given; shall be custodian of the corporate seal, records,
documents and papers of the National Trust Company; shall provide for the
keeping of proper records of all transactions of the National Trust Company;
shall have and may exercise any and all other powers and duties pertaining by
law, regulation or practice, to the Office of Cashier, or imposed by these
Bylaws; and shall also perform such other duties as may be assigned from time to
time, by the Board of Directors.

          Section 4.5. Other Officers. The Board of Directors may appoint one or
more Executive Vice Presidents, Senior Vice Presidents, Assistant Vice
Presidents, one or more Assistant Secretaries, one or more Assistant Cashiers,
one or more Managers and Assistant Managers of offices and such other officers
and attorneys in fact as from time to time may appear to the Board of Directors
to be required or desirable to transact the business of the National Trust
Company. Such officers shall respectively exercise such powers and perform such
duties as pertain to the several offices, or as may be conferred upon, or
assigned to, them by the Board of Directors, the Chairperson of the Board, or
the President. The Board of Directors may authorize an officer to appoint one or
more officers or assistant officers.

          Section 4.6. Tenure of Office. The President and all other officers
shall hold office for the current year for which the Board was elected, unless
they shall resign, become disqualified, or be removed; and any vacancy occurring
in the Office of President shall be filled promptly by the Board of Directors.

          Section 4.7. Resignation. An officer may resign at any time by
delivering notice to the National Trust Company. A resignation is effective when
the notice is given unless the notice specifies a later effective date.

                                   ARTICLE V

                             Fiduciary Activities

          Section 5.1. Trust Department. There shall be a department of the
National Trust Company known as the Trust Department that shall perform the
fiduciary responsibilities of the National Trust Company.

          Section 5.2. Trust Officer. There shall be a Trust Officer of this
National Trust Company whose duties shall be to manage, supervise and direct all
the activities of the Trust Department. Such persons shall do or cause to be
done all things necessary or proper in carrying on the business of the Trust
Department according to provisions of law and applicable regulations; and shall
act pursuant to opinion of counsel where such opinion is deemed necessary.
Opinions of counsel shall be retained on file in connection with all important
matters pertaining to fiduciary activities. The Trust Officer shall be
responsible for all assets and documents held by the National Trust Company in
connection with fiduciary matters.

                                      -5-

 
          The Board of Directors may appoint other trust officers of the Trust
Department, as it may deem necessary, with such duties as may be assigned.

          Section 5.3. Trust Investment Committee. There shall be a Trust
Investment Committee of this National Trust Company composed of not less than
two members, who shall be capable and experienced officers or directors of the
National Trust Company. All investments of funds held in a fiduciary capacity
shall be made, retained or disposed of only with the approval of the Trust
Investment Committee, and the Committee shall keep minutes of all its meetings,
showing the disposition of all matters considered and passed upon by it. The
Committee shall, promptly after the acceptance of an account for which the
National Trust Company has investment responsibilities, review the assets
thereof, to determine the advisability of retaining or disposing of such assets.
The Committee shall conduct a similar review at least once during each calendar
year thereafter and within 15 months of the last such review. A report of all
such reviews, together with the action taken as a result thereof, shall be noted
in the minutes of the Committee.

          Section 5.4. Trust Audit Committee. The Board of Directors shall
appoint a committee of not less than two directors, exclusive of any active
officer of the National Trust Company, which shall, at least once during each
calendar year make suitable audits of the Trust Department or cause suitable
audits to be made by auditors responsible only to the Board of Directors, and at
such time shall ascertain whether the Department has been administered according
to law, Part 9 of the Regulations of the Comptroller of the Currency, and sound
fiduciary principles. (Amended 8/5/97)

          Section 5.5. Fiduciary Files. There shall be maintained in the Trust
Department files all fiduciary records necessary to assure that its fiduciary
responsibilities have been properly undertaken and discharged.

          Section 5.6. Trust Investments. Funds held in a fiduciary capacity
shall be invested according to the instrument establishing the fiduciary
relationship and local law. Where such instrument does not specify the character
and class of investments to be made and does not vest in the National Trust
Company a discretion in the matter, funds held pursuant to such instrument shall
be invested in investments in which corporate fiduciaries may invest under local
law.

                                  ARTICLE VI

                         Stock and Stock Certificates

          Section 6.1 Transfers. Shares of stock shall be transferable on the
books of the National Trust Company, and a transfer book shall be kept in which
all transfers of stock shall be recorded. Every person becoming a shareholder by
such transfer shall, in proportion to his shares, succeed to all rights of the
prior holder of such shares.



                                      -6-

 
          Section 6.2. Stock Certificates. Certificates of stock shall bear the
signature of the President (which may be engraved, printed or impressed), and
shall be signed manually or by facsimile process by the Secretary, Assistant
Secretary, Cashier, Assistant Cashier, or any other officer appointed by the
Board of Directors for that purpose, to be known as an Authorized Officer, and
the seal of the National Trust Company shall be engraved thereon. Each
certificate shall recite on its face that the stock represented thereby is
transferable only upon the books of the National Trust Company properly
endorsed.

                                  ARTICLE VII

                                Corporate Seal

          The President, the Cashier, the Secretary or any Assistant Cashier or
Assistant Secretary, or other officer thereunto designated by the Board of
Directors, shall have authority to affix the corporate seal to any document
requiring such seal, and to attest the same. Such seal shall be substantially in
the following form:

                                 ARTICLE VIII

                           Miscellaneous Provisions

          Section 8.1. Fiscal Year. The Fiscal Year of the National Trust
Company shall be the calendar year.

          Section 8.2. Execution of Instruments. All agreements, indentures,
mortgages, deeds, conveyances, transfers, certificates, declarations, receipts,
discharges, releases, satisfactions, settlements, petitions, schedules,
accounts, affidavits, bonds, undertakings, proxies and other instruments or
documents may be signed, executed, acknowledged, verified, delivered or accepted
in behalf of the National Trust Company by the Chairperson of the Board, or the
President, or any Executive Vice President, or any Vice President, or the
Secretary, or the Cashier. Any such instruments may also be executed,
acknowledged, verified, delivered or accepted in behalf of the National Trust
Company in such other manner and by such other officers as the Board of
Directors may from time to time direct. The provisions of this Section 8.2. are
supplementary to any other provision of these Bylaws.

          Section 8.3. Records. The Articles of Association, the By-laws and the
proceedings of all meetings of the shareholders, the Board of Directors, and
standing committees of the Board, shall be recorded in appropriate minute books
provided for the purpose. The minutes of each meeting shall be signed by the
Secretary, Cashier or other Officer appointed to act as Secretary of the
meeting.



                                      -7-

 
                                  ARTICLE IX
 
                                    By-laws

          Section 9.1. Inspection. A copy of the By-laws, with all amendments
thereto, shall at all times be kept in a convenient place at the Main Office of
the National Trust Company, and shall be open for inspection to all
shareholders, during banking hours.

          Section 9.2. Amendments. The By-laws may be amended, altered or
repealed, at any regular meeting of the Board of Directors, by a vote of a
majority of the total number of the Directors.



                                      -8-

 
                                                                       EXHIBIT 6


                            CONSENT OF THE TRUSTEE

          Pursuant to the requirements of Section 321(b) of the Trust Indenture
Act of 1939, as amended, in connection with the proposed issuance by Prime
Medical Services, Inc. of its Senior Subordinated Notes, 8.75% Due 4/1/2008 and
its 7 1/8% Notes Due 2007, we hereby consent that reports of examination by
Federal, State, Territorial or District authorities may be furnished by such
authorities to the Securities and Exchange Commission upon request therefor.

                                        STATE STREET BANK AND TRUST COMPANY
                                                  OF MISSOURI N.A.


                                        By: /s/ ROBERT A. CLASQUIN
                                           -------------------------------------
                                              Robert A. Clasquin
                                              Assistant Vice President

Dated:  April 14, 1998

 
             STATE STREET BANK AND TRUST COMPANY OF MISSOURI, N.A.
                      CONSOLIDATED STATEMENT OF CONDITION
                                    FEB-98

 
 
ASSETS                               1998          1997
                                 ------------  ------------
 
 Cash and Due from Bank           $  703,340    $  414,485
 
 Total Investment Securities         292,500       292,500
 
 Total Premises and Equipment         11,171             0
 
 Accrued Income Receivable           246,874       170,046
 
 Other Assets                              0             0
 
 Goodwill Net                      8,362,411     8,647,287
                                  ----------    ----------
TOTAL ASSETS                      $9,616,297    $9,524,318
                                  ----------    ----------
 
LIABILITIES
 
 Accrued Tax and Other              (295,235)     (375,233)
 
 Unearned Revenue                    206,427       289,013
                                  ----------    ----------
TOTAL LIABILITIES                 $  (88,808)   $  (86,221)
                                  ----------    ----------
 
STOCKHOLDERS EQUITY
 
 Common Stock                        500,000       500,000
 
 Paid in Surplus                   9,250,000     9,250,000
 
 Retained Earning                    (44,894)     (139,461)
                                  ----------    ----------
TOTAL STOCKHOLDERS EQUITY         $9,705,106    $9,610,539
                                  ----------    ----------
TOTAL LIABILITIES AND
  STOCKHOLDERS EQUITY             $9,616,297    $9,524,318
                                  ==========    ==========