“But darlin’ can’t you see my signals turn from green to red
And with you I can see a traffic jam straight up ahead.”
— Jimi Hendrix,
Crosstown Traffic, 1968
I went to high school and learned to drive in a small town in Nova Scotia. Back then, there were no traffic lights in this town. There was but one lonely flashing light across a “busy” intersection, red on one side, amber on the other.
Of course, after my childhood in Toronto and Europe, I was familiar with traffic signals. I remember how strange the lights seemed in Europe, changing to amber before turning red then again before turning green. This sequence began to make sense only when I realized that most transmissions were manual and the amber before the green seemed to say: OK, time to engage the clutch and put your vehicle in gear. Ready, set, go!
It’s not difficult to imagine the chaotic jumble of horse-drawn carriages and pedestrians all trying to claim right-of-way on busy city streets, before the advent of the automated traffic signal.
In 1868 in London, England, a system invented by J.P. Knight, based on the system used to control train traffic, was installed on the corner of George and Bridge Streets, near London’s House of Commons. Gas was used to power the lights, but a human was needed to operate the system. For about a month, everything on the corner of George and Bridge worked smoothly until a gas leak, explosion and resulting injury to the police officer operating the system, signalled the end of the traffic signal for the time being.
It would be more than 40 years before the first electric traffic signal would be installed on the planet.
In 1907, the first traffic island was built in San Francisco, Calif. In 1911, the state of Michigan painted the first centre dividing line. A year later, Lester Wire, a police officer in Salt Lake City, Utah, mounted a handmade wooden box with coloured red and green lights on a pole using electricity from overhead trolley wires to power the “traffic light.”
In 1914, what is considered the world’s first electric traffic signal, based on a design by James Hoge, was installed on the corner of Euclid Avenue and East 105th Street in Cleveland, Ohio. Still manually controlled by a switch inside a control booth, the system was set up in such a way that conflicting signals were impossible.
The first amber light switched on in 1920, when William Potts, a police officer from Detroit, invented several systems of automatic electric traffic lights including an overhanging four-way, red, green, and yellow light system.
The automatic system relieved police officers of the tedious duty of changing the lights manually. Specific timed intervals were set up to control the changing of the lights but you can imagine how annoying it would be to sit at a deserted intersection, waiting for the specified time to elapse to get the green light.
Inventor Charles Adler Jr. installed a microphone on a pole at an intersection. A vehicle would stop and the driver would honk the horn of the vehicle. The microphone on the pole would pick up the honking and the light would change.
I want to believe that people were more patient during those times. However, this system may well have created the first occurrence of road rage. As drivers on all sides of the intersection indignantly felt it was their right-of-way, they would begin impatiently honking, wreaking havoc on the traffic situation, adding an inordinate amount of noise pollution to the neighbourhood.
It’s a basic human instinct to want to control one’s environment. My husband boasts about playing “Traffic God” in the late 1960s in his hometown of Moncton, New Brunswick: “A few of us knew of a spot on the pavement at Macbeath Avenue and Mountain Road, in the left-turning lane, that ambulances and fire trucks used to trip the light on Mountain Road to go red so the light on Macbeath would turn green.”
He crows: “I never had to wait for the light to change on Macbeath Avenue!”
The rudimentary sensor in the pavement has been replaced by a more sophisticated system known as traffic signal pre-emption. Operators of emergency vehicles play Traffic God with the lights of an intersection. There is a controller mounted on each traffic light. The emergency vehicle has an emitter that sends a signal to the controller. The traffic light ahead turns green in order to clear traffic blocking the emergency vehicle and stop traffic coming from other directions.
Obviously, the system improves safety at busy intersections and helps produce faster, safer emergency response.
The seemingly simple, effective traffic light: a colourful thing of beauty and control.