No person shall park a vehicle for any purpose or period of time other than for the expeditious loading or unloading of passengers or merchandise in any place marked by the municipality as a loading and unloading zone. Any applicant or any number of applicants may join together for the purpose for applying for such loading or unloading zone, and such applicant or applicants shall pay a reasonable annual charge for the use of such zone, such charge to be determined by the City Commission.