(a) Except as provided in subsections (b) and (c) of this section, each required stop or turn signal shall be given:
(1) By hand and arm in conformity with § 21-606 of this subtitle; or
(2) By signal lamps.
(b) Each motor vehicle in use on a highway shall be equipped with and the required signal given by signal lamps, if the distance from the center of the top of the steering post to the left outside limit of the body, cab, or load of the vehicle is more than 24 inches.
(c) Each motor vehicle in use on a highway shall be equipped with and the required signal given by signal lamps if, for any vehicle or combination of vehicles, the distance from the center of the top of the steering post to the rear limit of the body or load is more than 14 feet.
Structure Maryland Statutes
Title 21 - Vehicle Laws -- Rules of the Road
Subtitle 6 - Turning and Starting; Signals on Stopping, Turning, and Starting
Section 21-601 - Required Position and Method of Turning at Intersections or Crossovers
Section 21-602 - U-Turn on Curve or Crest of Grade Prohibited
Section 21-603 - Starting Vehicle
Section 21-604 - Turning, Slowing, and Stopping Movements; Required Signals