No person other than an officer of the police department or members of the fire protection district or a civilian authorized by the chief of police or a person authorized by law shall direct or attempt to direct traffic by voice, hand or other signal, except that persons may operate, when and herein provided any mechanical pushbutton signal erected by order of the city traffic engineer.
(Ord. 98 § 1 (part), 1993: Ord. 3 § 1 (part), 1991: prior code § 12.03.003)