ALBERT C. RITCHIE, GOVERNOR. 1253

application for registration has been made. Such computation
shall be based upon the mileage to be traversed by said motor ve-
hicles upon all highways having a hard, smooth surface, composed
of gravel, shells, crushed stone, concrete, paving blocks, asphalt,
other similar substances. The State Roads Commission shall
have authority, in disputed cases, to determine which roads
and streets upon which such motor vehicles are to be operated
should be included in the computation. The State Roads Com-
mission, after making such computation, shall forthwith cer-
tify the same to the Commissioner of Motor Vehicles, where-
upon the fee shown to be payable by said computation shall
immediately be paid by such motor vehicle owner to the Com-
missioner of Motor Vehicles.

252. All motor vehicles, except when used exclusively for
the transportation of pupils to and from public and/or private
schools, operating for hire over the improved Roads and
Streets of this State or of any county or municipality thereof
on regular schedules or between fixed termini, including those
used by corporations, groups of individuals and associations
engaged in the transportation of their stockholders, share-
holders or members, whether on the cooperative plan or
otherwise, shall be subject to the provisions of this sub-title,
except that the public duties of a common carrier shall not
thereby be imposed on the owner of any such vehicle not
actually engaged in public transportation.

253. Except as hereinafter provided, each and every such
motor vehicle so registered shall operate only on the route and
schedule set forth in said application during the year for which
said license is issued. It shall be the duty of the Commis-
sioner of Motor Vehicles, upon the presentation of a permit
from the Public Service Commission of Maryland, authoriz-
ing the motor vehicle owner to operate on a certain route,
to furnish the motor vehicle owner with a distinguishing
plate or marker. No such motor vehicle owner shall change
said schedule or route of his motor vehicle during any year
for which a certificate has been issued, without a permit, in
writing, made in duplicate, from the Public Service Com-
mission of Maryland, a copy of which shall be sent to the
Commissioner of Motor Vehicles before said schedule is
changed, whereupon a proper readjustment of charges shall
be made upon the basis aforesaid. But nothing in this sub-
title shall be construed to prevent an owner or operator of
such regularly licensed vehicles from replacing in an emer-
gency such vehicles by a substitute vehicle in order to main-
tain the schedule approved as herein provided or in an
emergency from operating, temporarily, reserve vehicles on