6-1-2 DEFINITIONS.
   Where words and phrases used in the traffic code are defined by State law, such definitions apply to their use in said traffic code and are adopted by reference. Those definitions so adopted that need further definition or are reiterated, and other words and phrases used herein, have the following meanings:
(Code of Iowa, Sec. 321.1)
   1.   “Business District” means the territory contiguous to and including a highway when 50 percent or more of the frontage thereon for a distance of 300 feet or more is occupied by buildings in use for business.
   2.   “MPH” means miles per hour.
   3.   “Park” or “parking” means the standing of a vehicle, whether occupied or not, otherwise than temporarily for the purpose of and while actually engaged in loading or unloading merchandise or passengers.
   4.   “Police officer” means every officer authorized to direct or regulate traffic or to make arrests for violations of traffic regulations.
   5.   “Residence district” means the territory contiguous to and including a highway not comprising a business, suburban or school district, where 40 percent or more of the frontage on such a highway for a distance of 300 feet or more is occupied by dwellings or by dwellings and buildings in use for business.
   6.   “School district” means the territory contiguous to and including a highway for a distance of 200 feet in either direction from a schoolhouse.
   7.   “Stand” or “standing” means the halting of a vehicle, whether occupied or not, otherwise than for the purpose of and while actually engaged in receiving or discharging passengers.
   8.   “Stop” means when required, the complete cessation of movement.
   9.   “Stop” or “stopping” means when prohibited, any halting of a vehicle, even momentarily, whether occupied or not, except when necessary to avoid conflict with other traffic or in compliance with the directions of a police officer or traffic control sign or signal.
   10.   “Suburban district” means all other parts of the City not included in the business, school, or residence districts.
   11.   “Traffic control device” means all signs, signals, markings, and devices not inconsistent with this title, lawfully placed or erected for the purpose of regulating, warning, or guiding traffic.
   12.   “Vehicle” means every device in, upon, or by which any person or property is or may be transported or drawn upon a public highway, street, or alley.