The Board of Recreation and Park Commissioners is hereby authorized and directed to post and maintain appropriate signs indicating that parking is limited or prohibited on any park-drive, park-road, or at any other place within parks, playgrounds and recreation areas owned or controlled by the City during such hours, or on such days, or both, as is necessary for the safety of the public or the reasonable use or enjoyment by the public of the park, playground or recreation area, and whenever such authorized signs are in place, giving notice thereon that parking is limited or prohibited during such hours or on such days as are indicated on the signs, it shall be unlawful for any person to park any vehicle, motor vehicle or motorcycle at any time during such hours or on such days, or for any length of time prohibited as indicated by such signs.