21100. Local authorities may adopt rules and regulations by ordinance
or resolution regarding the following matters.
   (c) Regulating traffic by means of traffic officers
   (d) Regulating traffic by means of official traffic control devices
meeting the requirements of Section 21400.
   (e) Regulating traffic by means of any person given temnporary or
permanent appointment for such duty by the local authority whenever
official traffic control devices are disabled or otherwise inoperable, at the
scenes of collisions or distasters, or at such locations as my require traffic
direction for orderly traffic flow.
(h) Operation of bicyles, and, as specified in Section 21114.5, electric
cars by physically disabled persons, or persons 50 years of age or older,
on the public sidewalks.