Section 21 Restriction on carriage of persons on bicycles
It shall not be lawful for more than one person to be carried on a road on a bicycle not propelled by mechanical power unless it is constructed or adapted for the carriage of more than one person ; and if a person is carried on a bicycle in contravention of this section, each of the persons carried shall be guilty of an offence. In this section references to a person carried on a bicycle include references to a person riding the bicycle and the reference to a road includes a reference to a bridleway.