except where there is clearly no pedestrian or bicycle (hereinafter referred to in this Article as "pedestrian, etc.") ahead of the vehicle, etc. In this case, if any pedestrians, etc. are crossing or are about to cross the pedestrian crossing, etc. ahead of the vehicle, etc., the vehicle, etc. shall come to a stop immediately before said pedestrian crossing, etc. and shall not obstruct the passage of such pedestrians, etc.