(A) The driver of any vehicle and the motorman of any streetcar shall obey the instructions of any official traffic-control device applicable thereto placed in accordance with the provisions of this subchapter, unless otherwise directed by a traffic or police officer, subject to the exceptions granted the driver of an authorized emergency vehicle in this subchapter.
(B) No provision of this subchapter for which signs are required shall be enforced against an alleged violator if at the time and place of the alleged violation an official sign is not in proper position and sufficiently legible to be seen by an ordinarily observant person. Whenever a particular section does not state that signs are required, such section shall be effective even though no signs are erected or in place.
(1991 Code, § 19-69) Penalty, see § 72.999