(a) An operator may drive on an improved shoulder to the right of the main traveled portion of a roadway if that operation is necessary and may be done safely, but only:
(1) to stop, stand, or park;
(2) to accelerate before entering the main traveled lane of traffic;
(3) to decelerate before making a right turn;
(4) to pass another vehicle that is slowing or stopped on the main traveled portion of the highway, disabled, or preparing to make a left turn;
(5) to allow another vehicle traveling faster to pass;
(6) as permitted or required by an official traffic-control device; or
(7) to avoid a collision.
(b) An operator may drive on an improved shoulder to the left of the main traveled portion of a divided or limited-access or controlled-access highway if that operation may be done safely, but only:
(1) to slow or stop when the vehicle is disabled and traffic or other circumstances prohibit the safe movement of the vehicle to the shoulder to the right of the main traveled portion of the roadway;
(2) as permitted or required by an official traffic-control device; or
(3) to avoid a collision.

(c) A limitation in this section on driving on an improved shoulder does not apply to:
(1) an authorized emergency vehicle responding to a call;
(2) a police patrol;
(3) a bicycle; or
(4) a slow-moving vehicle, as defined by § 547.001.