Ampelmännchen, little traffic light men, are a Berlin phenomenon. In 1961, a traffic psychologist introduced the first pedestrian signals in East Berlin. The desgin was created because road-users react more quickly to appealing symbols.
Prior to German reunification in 1990, the two Germanys had different Ampelmännchen. It's a generic human figure in West Germany while in East Germany the figure wears a hat.
After unification in 1990 there were attempts to standardise all traffic signs to the West German standard. The East German lights were dismantled and replaced. This led to calls to save the East German Ampelmännchen as a part of East German culture. In 2005, the little man in the hat made his return to East Berlin.
The Ampelmännchen is one of the few features of communist East Germany to have survived the Iron Curtain. Ampelmännchen has acquired cult status and is a popular souvenir item in Ampelmännchen stores.
There are currently three Ampelmännchen variations in Germany. The old East German version, the old West German version, and a pan-German Ampelmännchen that was introduced in 1992. Every German state gets to decide which version to use.