Are Traffic Signs Obsolete?

zuikaku writes: Der Spiegel has an article titled European Cities Do Away with Traffic Signs which reports that seven cities and regions in Europe are doing away with traffic signs, signals, painted lines, and even sidewalks. With the motto "Unsafe is Safe", the idea is that, when faced with an uncertain, unregulated situation, drivers will be naturally cautious and courteous. Then again, they may end up with streets jammed with pedestrians, bicyclists, and cars like some places in India and China.