331.43 SCHOOL CROSSINGS.
   (a)   The Director of Public Safety is hereby directed to designate school crossings upon such streets in the City as are used by school children in going to and from schools. School crossings may be designated at such crossings where in the discretion of the Director of Public Safety, school children cross in such numbers as to constitute a traffic hazard or so as to be exposed to traffic hazards.
   (b)   The crossings designated by the Director of Public Safety in accordance with subsection (a) hereof as school crossings shall be conspicuously marked and appropriate signs shall be erected and maintained in the vicinity of each crossing. Such signs may be so constructed as to display the word "STOP" when safety stops shall be required and so that the word "STOP" does not appear thereon during such time as safety stops are not required; provided, however, that nothing herein contained shall prohibit the regulation of traffic at school crossings by any other lawful means.
   (c)   The Director of Public Safety is hereby directed to provide by rule the times during which safety stops shall be required at school crossings and to provide for the display of the word "STOP" upon the signs described in subsection (b) hereof during such times as safety stops shall be required. It is the intention of this section to require safety stops at school crossings during such times as children are going to and coming from school and to permit the free flow of traffic, at reasonable lawful speeds, through and over such crossings during other intervals of time.
   (d)   During such time as the word "STOP" is displayed on the signs described in subsection (b) hereof, when otherwise lawfully directed to do so, all vehicles before entering or crossing a designated school crossing shall execute a safety stop by coming to a full and complete stop, and shall yield the right of way to any person lawfully crossing such school crossing. The stops herein required shall be made for the purpose of permitting children upon a school crossing to cross the same in safety and to allow children about to cross such crossing to proceed.
(1964 Code Sec. 74.59)
   (e)   It is prima-facie lawful for the operator of a motor vehicle to operate the same at a speed not exceeding twenty miles per hour upon entering or crossing a designated school crossing zone.
   (f)   Whoever violates any provision of this section is guilty of a minor misdemeanor on a first offense; on a second offense within one year after the first offense, the person is guilty of a misdemeanor of the fourth degree; on each subsequent offense within one year after the first offense, the person is guilty of a misdemeanor of the third degree.