Reading the article “Watch out! Everyone’s jaywalking” in last week’s Sunday Times, one might have thought the story was about pedestrian behaviour in some undeveloped country where traffic lights and pedestrian crossings are alien concepts.

Sad to say, it happened right here in Singapore. Perhaps it’s time to re-educate Singapore road users that using traffic lights and pedestrian crossings is sign of progress, development and a civilised society.

What are traffic lights?

The traffic light is a signalling device positioned at a road junction or pedestrian crossing to indicate, using a universal colour code (red, amber and green) and a precise sequence (to aid the colour blind) to assign the right of way to vehicles on the road and pedestrians.

Red – this means traffic must stop. The pedestrian crossing will change to green to allow people to cross the road safely.
Green – this means traffic can go, provided it is safe to do so. The pedestrian crossing will be red.
Amber – this means traffic should stop unless the vehicle is too close to the stop line that it cannot stop safely.

The history of traffic lights

The evolution of modern traffic lights was a complex and continuous process. The very first traffic lights were installed near the House of Commons in London, England, by railway engineer J P Knight, in 1868. A traffic signal using red and green lights lit by lanterns, called a semaphore, was used to provide a safe crossing for pedestrians in a sea of horse-drawn traffic. Traffic officers would use a hand crank to change the signal.

Over in the United States, the first automated traffic light may have been invented and patented by Earnest Sirrine in 1910. The words “proceed” and “stop” were used to direct traffic instead of the use of red and green lights.

The idea of using red and green colours instead of words in an electric light was implemented a few years later by Lester Wire, a policeman, in Salt Lake City in 1912.

Later, in 1913, James Hoge of Cleveland, Ohio, patented a manually controlled electric traffic light system that used red and green lights displaying the words “stop” and “move”, and a warning buzzer. Hoge’s design allowed the police and fire stations to control the signals in emergencies.

William Ghiglieri of San Francisco, California, patented perhaps the first automatic traffic signal using red and green lights in 1917. His traffic signal had the option of being either manual or automatic.

The first four-way, three-colour traffic light was created by police officer William Potts in Detroit in 1920. Although there were other inventions before his, Potts was the first to include the amber light in his design to warn motorists that the light would change soon. As a government employee, Potts could not patent his invention.

In 1923, Garrett Morgan of Cleveland, Ohio, invented and patented the electric automatic traffic light, although it was not a precursor of the modern traffic light. Morgan’s patent was purchased by General Electric Corporation and provided the protection they needed to begin a monopoly on manufacturing traffic lights.