The Director of Veterinary Services may, where he considers it necessary to prevent the spread of tsetse fly, authorize the establishment of tsetse control pickets on any roads and recognized footpaths in accordance with regulation 3. Any person whether traveling on foot or by vehicle, and any person driving domestic animals, along any road or footpath on which a tsetse control picket has been established shall have the duty to stop at the picket and vehicles shall stop in a smudge house, i.e. a