When I'm on my morning walk I get flashed at regularly. It's not a pretty sight - one day the (a) culprit will come to grief.
400 vehicles an hour trigger this sign associated with an advisory 40 mph speed restriction through the bends between the woods on either side of the road.
Yesterday morning I grabbed my camera as the sign flashed up.
For other spontaneous interpretations follow the links at Carmi's Thematic-photographic-344.