Find out who the councilman(person) was that checked the law for the bicycles. Have a conversation with that person and find out how to get the law amended to accommodate the handicapped. Might have to speak with a lawyer to get the right wording  for a proposal to do so.  If you are lucky and know an ombudsman, it will be easier and possibly cheaper.  Might also want to get it specified that the bicycle/tricycle(recumbent) be primarily pedal powered with an electric assist. Yes such distinctions need be made when dealing with the law.