The streets, or parts thereof, described in Ch. 76, Sch. IV, are hereby designated as commercial loading and unloading zones and no person shall stop, stand or park a vehicle therein during the hours of 8:00 a.m. to 6:00 p.m. for any purpose other than the expeditious unloading and delivery or pickup and loading of materials and goods, and then only for a period not to exceed 30 minutes.
('84 Code, § 16-103)