Recently I did a road trip through Portugal. I always enjoy finding something new that they are doing in a country which has not yet spread to the rest of the world.
Along a number of Portuguese roads, you will see a sign marked "velocidade controlada" -- speed control -- and then a modest distance down the road will be a traffic light in the middle of nowhere. There is no cross street. This is an interesting alternative to the speed bump or other "traffic calming" systems.