In 1900 there were no rules of the road. There were no signs or signals. Horses, horse drawn vehicles, cars, bicycles and pedestrians all shared the road. In New York in 1900 fatalities from horse drawn vehicles were 75% higher than fatalities from automobiles in 2003. It was worse in Chicago, where in 1916 horse accident fatalities were 700% higher than in auto fatalities in 1997. (Morris) It might seem counterintuitive to us now, but automobiles actually brought some relief. Still Urban populations were rising and so was urban traffic. National traffic had doubled between 1885 and 1905. (Morris)

Because there were no traffic signs or signals there were no reliable channels of communication between users of the road. In the din of the city speech was drown out by noise. So travel in the city was an endless game of chicken.


In 1900 William Phelps Eno published “Reforming Our Street Traffic Urgently Needed” in Rider and Driver magazine. He called for the use of traffic signs to ease the chaos of the streets. He subsequently became instrumental in the movement to establish traffic regulations and signage. (Greenbaum and Rubinstein) In 1920 he published “The Science of Highway Traffic Regulation” which is recognized as the seminal work on traffic regulation and signage. (Eno) The essential difficulties with implementation of traffic regulations were development of rational rules, standardization of rules, developing best methods of communicating those rules and finally convincing travelers to adopt the rules and regulations. The regulations are ideas. Signs are means of communicating of those ideas. The idea that is being communicated is a social contract. There was a challenge in convincing the “freedom loving” population that civility is beneficial to everyone. Implementation of rules and regulations requires travelers acting on the ideas that are the communicated by the signs. So the real thing that these signs are talking about is the act of driving.



Traffic lights are now a standard form of communication. They deliver useful information to drivers and pedestrians. For drivers, green means go. Red means stop. Yellow means caution. For pedestrians, white means go and orange means stop. For pedestrians there are also sound signals. A chirping sound means go. As your time to cross runs out the chirp changes to a croak. Pedestrians also get iconic signals. The icon of a walking man means go.

When my son was four he wanted to know the name of the walking man icon. He was upset that the walking man icon did not refer to a specific person. I did not know his name. So my son named him "walking guy" and he was satisfied. For him it was better that a symbol refer to a specific thing, especially if it was a symbol of a person. From that time on, when the walking guy would light up and begin chirping I would say “It’s walking guy. Time to cross the street.”. So he [my son] would get the information through two channels: sight and sound: I told him that it was time to cross and the chirp told him that it was time to cross and the light told him that it was time to cross so there was redundancy in the message. This is important because at four years old life is full of distractions. Those distractions are noise that can obscure the signal. As we grow up we learn to filter out the noise. We learn the nature of communication. We learn what signals to act upon and what signals to ignore. It was important that he learn the meaning of signals and signs. “Look both ways before you cross"

Traffic is dangerous.

Traffic signals reduce the danger for both pedestrians and drivers. The average SUV weighs 2.2 tons. (“Criticism of Sport Utility Vehicles.”) The average human weighs 164.7 lbs. (“Body Weight.”) Luckily we are getting fatter, but the SUV still wins. The driver of the SUV is bound by law to abide by the traffic signals. The driver is also signaling. The red turn signal on the SUV is flashing. The break lights were lit, but now they are off. Look out -- The SUV is going to turn. The head lights, brake lights, backing lights and turn signals tell other travelers what the SUV is going to do. Of course it is not the intention of the SUV. It is the intention of the driver of the SUV. So when I say SUV, I hope that you understand that I am actually referring to the driver who uses the SUV as a signaling device. The SUV itself is a signal. It signals power and waste.



Traffic signals communicate through color, but we do not all see colors in the same way. My uncle "Mo" was color blind. Sometimes he used that as an excuse to run red lights. Color blindness is the "…inability or decreased ability to see color…" (“Color Blindness.”). Color blindness affects primarily men. About 7% of adult males in the US are color blind (“Color Blindness.”). There are different types of color blindness. Each type affects perception of color in a particular way. Protanopia and deuteranopia are the most common types of color blindness (“Color Blindness.”).

This is a flag seen by a person with no color blindness.

This is how a person with protanopia sees the flag.

This is how a person with deuteranopia sees the flag.

Tritanopia is a rare type of color blindness. This is how a person with tritanopia sees the flag.

So how do people with color blindness percieve traffic lights?
no color blindness - 1
protanopia - 2
deuteranopia - 3
tritanopia - 4

So how do people with color blindness know when to stop and when to go? Traffic signals also communicate through position of the lights. In the US red is on top, yellow is in the middle and green is on the bottom. So red is associated with top and means stop, yellow is associated with middle and means caution and green is associated with bottom and means go. This redundancy is necessary for a safety margin. Because of this redundancy in the signal Uncle Mo does not have any excuse to run red lights and ram other cars.


In Halifax, Nova Scotia traffic light communicate through the shape of the light. Square means stop. Lozenge means caution. Circle means go. But these lights are arranged in horizontal order. So Red, Square and Left position are all associated with each other and they all mean stop. And so on with the other positions, shapes and colors. ("Traffic Light")

("Traffic Light")

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Semiotics is the study of signs. Humans communicate with signs and signs are communication. From the stand point of semiotics anything made by people communicates something and is therefore a sign. A stop sign is a sign. The street light is a sign. But a banana is not a sign, unless it has been put in a meaningful place such as a get-well fruit basket. Then it is part of a sign that says "I care". A rock is not a sign unless it has been placed in a cairn. Then it is part of a sign that says someone was here and stacked up rocks for some reason. The meaning of signs is dependent on culture and context. The cairn may be burial mound or it may be historical marker or it may be a simple expression of human’s need to alter their environment.

The word “dog” is a sign because it is synthetic. It is synthetic because it was made by people. The word dog means a four legged mammal that likes to lick peanut butter off of a spoon and gets it’s mouth all gummed up. Many people find this behavior amusing so they keep dogs as pets. But is a dog this dog or that dog. Does the word dog mean that dog Spot or that dog Fido or my dog Gretta? Dog can be any one of these dogs. It is not a specific dog. So the word dog means the concept of “dogness”. Fido is a dog because Fido has all the properties of dogness. Dog is a blueprint for all dogs and any dog is an instance of that blueprint. (Herbert)

The most widely used semiotic model and terminology is based on linguistic theory developed by Ferdinand de Saussure.

In the Saussurean Model of Semiotics a sign has constituent parts. The signifier is the physical aspect of the sign. The word dog is a signifier. The signified is the concept of the sign. The concept of dogness is the signified. A specific instance of the concept is the referent. Fido is a referent for the word dog. So The signifier performs the act of signification and signifies the signified which refers to the referent. Simple. But Chien also signifies the concept of dogness. And pero signifies the concept of dogness. Different words can signify the same concept. This means that the signifier and the signified are not inextricable in other words the symbol and the idea are two different things in other word the signifier and the idea can be separated in other words the word and it’s meaning are not permanently bound in other words I can use other words to mean the same thing. The concept is not tied to the words or symbols that communicate the concept. In semiotic terms the signifier is arbitrary.

But it would be disingenuous to argue that symbols are always completely arbitrary. In the case of traffic lights one could argue that red is the color of blood .:. Red is a warning to stop or die a bloody gruesome death. But then why not use orange as a warning to stop or die a fiery death? Or why not use yellow because it is the color most readily perceivable by the eye? Often we can only guess at the genesis of signifiers, and so, in effect they are arbitrary.

Spoken words are abstractions made of sounds. Those sound abstractions signify actual things or concepts. And written words signify spoken words that signify the actual concept or thing. So written words are two abstraction layers away from the actual thing or concept.

The natural genesis of some spoken words is obvious, like "woof", "meow" and "splash". The sound of word "woof" is meant to imitate the sound that a dog makes. The sound of the word "splash" is meant to imitate the sound of a rock plunging into water at speed. Onomatopoeia is the word that means when the sound of a word imitates the sound of the thing that it represents. Although the genesis of many (or perhaps originally all) words may have been an imitation of natural sound, most all have evolved into abstract sounds. They are now, in effect, arbitrary. Ironically Onomatopoeia is a word that has evolved beyond recognition of its original genesis. As a signifier it has become an arbitrary sound.

There are cultural spins to a onomatopoeia. English speaking roosters say "cock-a-doodle-doo". We [english speakers] feel that those phonemes are accurate imitations of the sound that a rooster makes. Spanish speaking roosters say "qui-quiri-quí" and French speaking roosters say "co-cori-co". Each language has their own pet phonemes that imitate rooster speach. Is this due to cultural perceptions or are these words in the early stages of evolution away from onomatopoeia or do Spanish roosters have a spanish accent and French roosters a french accent and so on...?

Some people think that when dogs bark they say "woof", but some people think that when dogs speak they say "bark". I am not going to admit that I watch funny pet videos on YouTube, I only notice them because someone else regularly watches them. But I know that the sound articulations of dogs are well documented on youtube and that dogs can be very articulate. This means that there can be many phonetic constructions that serve as onomatopoeia for the speech of dogs: "woof", "growl", "grrr" and "bark".

But dogs do not construct very complex language with their articulations. And the sounds that they articulate probably do not signify complex concepts. When a dog says "bark" he is probably not signifying a part of a tree. Humans are unique in the complexity of both language structures and conceptual structures.