702 LAWS OF MARYLAND. [CH. 356

mission is hereby authorized and empowered, subject to the
provisions of this sub-title:

(a) To construct, operate and maintain bridges over and
tunnels under rivers and navigable waters which are wholly
or partly within the State;

(b) To construct, operate and maintain, wholly within the
State, tunnels through hills and mountains; and

(c) To issue revenue bonds of the State, payable solely from
earnings, to pay the cost of such bridges and tunnels.

But no bridge or tunnel shall be constructed under the pro-
visions of this sub-title unless the cost of the project, as esti-
mated by the State Roads Commission, shall exceed the sum
of Seven Hundred and Fifty Thousand Dollars, nor unless the
construction of such bridge or tunnel shall be included in the
above-mentioned plan filed with the Secretary of the State
Roads Commission and approved by a majority of the mem-
bers of the Bridge Supervisory Committee, or, if the construc-
tion of such bridge or tunnel shall not be included in such
plan or if such plan shall not theretofore have been filed,
unless such construction shall be approved by said Bridge
Supervisory Committee.

The cost of such construction shall be paid solely from the
proceeds of such revenue bonds and from any grant from
the Federal Government or any agency thereof.

107. CREDIT OF STATE NOT PLEDGED. Revenue bonds issued
under the provisions of this sub-title shall not be deemed to
constitute a debt of the State of Maryland or a pledge of the
faith and credit of the State, but such bonds shall be payable
exclusively from the fund hereinafter provided therefor from
tolls and revenues. All such bonds shall contain a statement
on their face that the State of Maryland is not obligated to
pay the same or the interest thereon except from revenues of
the project or projects for which they are issued and that the
faith and credit of the State is not pledged to the payment of
the principal or interest of such bonds. The issuance of
revenue bonds under the provisions of this sub-title shall not
directly or indirectly or contingently obligate the State to
levy or to pledge any form of taxation whatever therefor or
to make any appropriation for their payment.

108. PRELIMINARY EXPENSES. The State Roads Commis-
sion is hereby authorized to expend out of its current funds
such moneys as may be necessary for the study of any con-
templated bridge or tunnel which the Commission after pre
liminary investigation believes to he of such probable benefit
to the public as to entitle the project to further investigation
and study, and the Commission is hereby authorized to use its
engineering and other forces for the purpose of making such