A parking space on private or public property that is reserved for persons who are disabled shall be marked by a sign affixed to a post or a building. Said sign shall be clearly visible to anyone directly approaching that particular space. Van-accessible spaces shall be allocated according to the requirements of the Americans with Disabilities Act of 1990 and regulations and guidelines promulgated pursuant thereto. One "van only" spot for every 5 spaces which are reserved for persons who are disabled is recommended. Failure to comply with the sign placement requirements of this section shall subject the property owner to a $250 fine, provided that the owner shall not be fined more than once in any 120-day period for the same violation.