It is unlawful for the operator of a vehicle to stop the vehicle for a period of time longer than is necessary for the loading or unloading of passengers or materials; provided that the loading or unloading of passengers shall not consume more than three minutes, nor the loading or unloading of materials more than 20 minutes, in any of the following places:
(A) At any curb where the grade of the street exceeds 10%;
(B) In any alley;
(C) In any loading zone;
(D) At any curb within 25 feet of a point on the curb opposite the center of the entrance to any hospital;
(E) At any curb within 50 feet of a point on the curb opposite the center of the entrance to any police station or fire station;
(F) In any marked bus stop (passenger only).
('86 Code, § 11.32.010) (Ord. 2479, passed - - ) Penalty, see § 11.32.015