No vehicle shall stop in any street, except for the purpose of parking as prescribed in this chapter, unless such stop is made necessary by the approach of fire apparatus, by the approach of a funeral or other procession which is given the right-of-way, by the stopping of a public conveyance, by the lowering of railway gates, by the giving of traffic signals, by the passing of some other vehicle or a pedestrian or by some emergency. In any case covered by these exceptions, such vehicles shall stop so as not to obstruct any footway, pedestrian aisle, safety zone, crossing or street intersection if such can be avoided.