Notwithstanding Article 17, paragraph (1), a standard bicycle may be ridden on a sidewalk in the following cases; provided, however, that this does not apply if an officer instructs a person riding a standard bicycle not to ride on the sidewalk, having found it necessary to do so in order ensure the safety of pedestrians:
if standard bicycles are permitted by road signs or markings to be ridden on the sidewalk;
if the person riding the standard bicycle is an elementary schooler, child not yet of school age, or any other person that Cabinet Order prescribes for whom riding a standard bicycle on a roadway is considered to be dangerous;
if, beyond as set forth in the preceding two items, roadway or traffic conditions are found to provide compelling circumstances for the person riding the standard bicycle to ride on the sidewalk so as to ensure safe progress.
In a case as referred to in the preceding paragraph, a person riding a standard bicycle must ride at reduced speed when on the part of the sidewalk between the center and the roadway (or the part of the sidewalk that road signs or markings designate as that on which standard bicycles are required to be ridden (hereinafter referred to in this paragraph as the "part of the sidewalk for use by standard bicycles"), if any), and must come to a stop if the bicycle's progress would prevent pedestrians from proceeding; provided, however, that, if there are no pedestrians proceeding down or about to enter the part of the sidewalk for use by standard bicycles, the person riding a standard bicycle may travel down that part of the sidewalk at a safe speed and in a safe manner, in keeping with sidewalk conditions.