There is an interesting debate going on in the UK at the moment between what roughly seems to be the food industry and the govt about the labelling of food. The food industry has opted for a system based on Guideline Daily Amounts (IGD website) and the Food Standards Agency has opted for a traffic light system. I don't want to go into the whys and wherefores of which system is better, because I'm not qualified to do that. Interesting however if we want to think about semiotics in the real world is the argument that the traffic light system is easier for people to understand (See this article from the BBC). I heard the interview with the Mum they quote there; she basically was in the store with her little kid running away from her and she said, 'I want to be able to understand things immediately. This is very clear to me.'
It got me thinking about 1) traffic lights and their origins. And also 2) their semiotic significance.
1) The origins of traffic lights seems to be widely accepted that they stem from railway signals which had a red lantern and a green lantern which were hidden alternatively by a semaphore arm. It has never been otherwise than Green was "go" and Red was "stop". Why Amber was introduced as "think about doing something" I don't know. It's an interesting case where a colour's coded meaning has come about because of its association with other colours which have very clear meanings.
2) Traffic lights are semiotically significant and also particularly interesting for this site because they are a perfect example of how a code become historically and culurally entrenched and then spreads. There is no ontological reason why red should be for danger and green for safety but it is now culturally embedded so much so that now that is what those colours mean.
or to put it another slightly more academic way:
"It should be noted that whilst the relationships between signifiers and their signifieds are ontologically arbitrary (philosophically, it would not make any difference to the status of these entities in 'the order of things' if what we call 'black' had always been called 'white' and vice versa), this is not to suggest that signifying systems are socially or historically arbitrary. Natural languages are not, of course, arbitrarily established, unlike historical inventions such as Morse Code. Nor does the arbitrary nature of the sign make it socially 'neutral' or materially 'transparent' - for example, in Western culture 'white' has come to be a privileged signifier (Dyer 1997). Even in the case of the 'arbitrary' colours of traffic lights, the original choice of red for 'stop' was not entirely arbitrary, since it already carried relevant associations with danger. As Lévi-Strauss noted, the sign is arbitrary a priori but ceases to be arbitrary a posteriori - after the sign has come into historical existence it cannot be arbitrarily changed (Lévi-Strauss 1972, 91). As part of its social use within a code (a term which became fundamental amongst post-Saussurean semioticians), every sign acquires a history and connotations of its own which are familiar to members of the sign-users' culture." This from a very useful website for students of semiotics by Daniel Chandler.
I realise that I've already talked about German traffic lights but don't worry, I don't think there will be many more posts on traffic lights.