Whenever any public school property and/or the areas of any public governing body or authority customarily or usually open to traffic by the public are posted by order of the appropriate school board or other proper authority or governing body in control of the property, then it shall be unlawful to drive, operate, stop, park or leave standing any vehicle on the property contrary to the posting.
(`87 Code, § 701.10) Penalty, see § 10.99