Deutsche Beschreibung THE PROJECT

: D wie Düsseldorf

:D Optical Signaling Systems

Optical signaling systems – what a kind of bureaucratic language! Everybody is calling this „traffic light“. Originally a traffic light was a kind of pending light in the middle of an intersection. This is still the case in some countries, but in Germany this almost completely ceased to exist.

Now let's talk about traffic lights in Düsseldorf. Düsseldorf has 620 traffic lights, connected to a traffic computer network, either via cable or via mobile network (GSM). Times where you could see large gray switchboards on every crossroad, full of process control computers, assembly groups, cables and wires are long gone. Meanwhile all traffic lights have been vamped up and because of various detectors, they are theoretically able to operate dependending on the actual traffic.

However, usually they are operating based on the time of day, following a special plan with morning peak, evening peak and if necessary night shutdown. This plan could be influenced by pedestrians, trams or buses which can request additional green lights.

Traffic management is quite a complex matter which depends on geographic conditions (traffic flows along with connections, separations, or crossings), or politically motivated decisions like prioritization and acceleration of public transport. The common goal is a streaming traffic flow, also known as phased traffic lights (in German: “green wave”).

Those nicely looking little men for pedestrians from former German Democratic Republic (GDR) do not exist in Düsseldorf, altough some of these imports from East Germany have been recognized in some cities in Western Germany. But Düsseldorf has another unique feature:

Yellow lights for pedestrians!

Let's come to the mystery now. This is a small Google Earth lookup task:

Find this place

If you are not able to find the solution – in case of emergency, you could visit a callbox at the Luegplatz in Oberkassel and get help.

Have fun!


Every geocache of the :D series contains a bonus code. Please write it down, you will need it in order to log the two bonus caches GC49RXJ and GC44Q3J!

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There is no geocache to find at the listed coordinates. No cache which is part of the :D series requires to trespass rail tracks or highways. Caches located on private property have been placed there with explicit permit of the owner. If a riddle requires visiting third party websites or downloading additional files, we guarantee that at the time of publish, they don't contain any virus or harmful software.

725 Jahre Düsseldorf

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