No person shall engage in any motor vehicle speed contest or exhibition of speed on any street or highway and no person shall aid or abet any motor vehicle speed contest or speed exhibition on any street or highway, except that a passenger shall not be considered as aiding and abetting. "Motor vehicle speed contest" or "exhibition of speed" are defined as one or more persons competing in speed in excess of the applicable speed limit in vehicles on the public street. (2008 Code § 17-278)