21209.  (a) No person shall drive a motor vehicle in a bicycle lane
established on a roadway pursuant to Section 21207 except as follows:

   (1) To park where parking is permitted.
   (2) To enter or leave the roadway.
   (3) To prepare for a turn within a distance of 200 feet from the
intersection.
   (b) This section does not prohibit the use of a motorized bicycle
in a bicycle lane, pursuant to Section 21207.5, at a speed no greater
than is reasonable or prudent, having due regard for visibility,
traffic conditions, and the condition of the roadway surface of the
bicycle lane, and in a manner which does not endanger the safety of
bicyclists.