(a) Regulations adopted by the Safety Director pursuant to Section 305.02 shall become effective immediately upon the installation or placement of such traffic control devices as are necessary to give notice of the existence of such regulations. Signs, signals, markings or other traffic control devices shall be sufficiently legible, and shall be installed or placed in such locations and sufficient in number as to be seen by an ordinarily observant person.
(b) Such regulations shall be issued in the manner and subject to the conditions and limitations as prescribed by ordinance. Copies of such regulations, when certified by the Safety Director, shall be competent evidence in all courts.
(c) Regulations shall continue to have the force and effect of ordinances passed by Council until superseded by subsequent regulations or by ordinance of Council. Violations of such regulations shall be subject to the penalties prescribed by Section 303.99.