708 LAWS OF MARYLAND. [CH. 356

interest, and (4) any premium upon bonds retired by call or
purchase as herein provided. The use and disposition of such
sinking fund shall be subject to such regulations as may be
provided in the resolution authorizing the issuance of bonds,
or in the trust indenture, but, except as may otherwise be
provided in such resolution or trust indenture, such sinking
fund shall be a fund for the benefit of all bonds without dis-
tinction or priority of one over another. Subject to the pro-
visions of the resolution authorizing the issuance of bonds or
of the trust indenture, any moneys in such sinking fund in
excess of an amount equal to one year's interest on all bonds
then outstanding may be applied to the purchase or redemp-
tion of bonds. All bonds so purchased or redeemed shall forth-
with be cancelled and shall not again be issued.

Notwithstanding any of the foregoing provisions of this
section, the Commission may, by resolution passed prior to
the issuance of the bonds or in the trust indenture covenant
to pay the cost of maintaining, repairing and operating any
project or projects constructed or acquired under the pro-
visions of this sub-title, and, inasmuch as such project or
projects will at all times belong to the State, such resolution
shall have the force of contract between the State and the
holders of the bonds issued for such project or projects.

Upon the letting of a contract for the construction of a
bridge or tunnel under the provisions of this sub-title, it shall
be the duty of the Commission to proceed with the construction
of any highways which may be necessary to connect such
bridge or tunnel with State highways and to complete the
construction of such connecting highways on or before the
date such bridge or tunnel shall be opened for traffic.

114. CESSATION OF TOLLS. When the particular revenue
bonds issued for any project or projects and the interest
thereon shall have been paid, or a sufficient amount shall have
been provided for their payment and shall continue to be held
for that purpose, the Commission shall cease to charge tolls
for the use of such project or projects, and thereafter such
project or projects shall be free; provided, however, that the
Commission may thereafter charge tolls for the use of any
such project, if not prohibited by any Federal Law, in the
event that tolls are required for maintaining, repairing and
operating such project due to the lack of funds from other
sources than tolls or in the event that such tolls shall have
been pledged by the Commission to the payment of revenue
bonds issued under the provisions of this sub-title for another
project or projects. But any such pledge of tolls of a project
to the payment of bonds issued for another project shall not
be effectual until the principal and interest of the bonds