Unless necessary to avoid conflict with other traffic, or unless a police officer or official traffic control device has so directed, no person may park a vehicle, whether occupied or not, except temporarily for the purpose of and while actually engaged in loading or unloading merchandise or passengers:
(A) Within 50 feet of the nearest rail of a railroad crossing;
(B) At any place where official signs prohibit parking.
(SDCL § 32-30-6.2) Penalty, see § 70.99