Traffic light

Why subscribe? • The ultimate action-packed science and technology magazine bursting with exciting information about the universe • Subscribe today and save an extra 5% with checkout code 'LOVE5' • Engaging articles, amazing illustrations & exclusive interviews • Issues delivered straight to your door or device Traffic lights, or traffic signals, are located on most major corners in cities and towns around the world. The red, yellow and green lights let us know when it is safe to drive through the intersection and when to walk across the street as well as when to stop and let other drivers, bikers and pedestrians take their turns to continue on their way. The first traffic signal Traffic jams were a problem even before the Railroads used a semaphore system with small arms extending from a pole to indicate whether a train could pass or not. In Knight's adaptation, semaphores would signal "stop" and "go" during the day, and at night red and green lights would be used. Gas lamps would illuminate the sign at night. A police officer would be stationed next to the signals to operate them. The world's first traffic signal was installed on Dec. 9, 1868, at the intersection of Bridge Street and Great George Street in the London borough of Westminster, near the Houses of Parliament and the Westminster Bridge, according to the BBC. It was a success and Knight predicted more would be installed. Ernest Stirrine's patent drawing for his traffic signal. (Image credit: U.S. Patent Office)...

In the first two decades of the 20th century, semaphore traffic signals like the one in London were in use all over the :22 It was controlled by a :23 The example in Ohio was the first time America tried to use a more visible form of traffic control that involved the use of semaphores. The device that was used in Ohio was designed based on the use of railroad signals. :382 In 1912, a traffic control device was placed on top of a tower in :33 Electric signals [ ] In 1912, the first electric traffic light was developed by :27–28 :32 The first four-way, three-colour traffic light was created by police officer :35 Los Angeles installed its first automated traffic signals in October 1920 at five locations on Broadway. These early signals, manufactured by the Acme Traffic Signal Co., paired "Stop" and "Go" semaphore arms with small red and green lights. Bells played the role of today's amber lights, ringing when the flags changed—a process that took five seconds. By 1923 the city had installed 31 Acme traffic control devices. Automatic electric signals [ ] In 1922 traffic towers were beginning to be controlled by automatic timers. The first company to add timers in traffic lights was Crouse Hinds. They built railroad signals and were the first company to place timers in traffic lights in :385 The main advantage for the use of the timer was that it saved cities money by replacing traffic officers. The city of :385 The introduction of automated traffic signals required a change of...

Table of Contents (click to expand) • • • • • • • The first traffic signal was invented in 1868 by J.P. Knight. In 1912, the first electric traffic light was invented by Lester Wire. The modern traffic light still uses this T-shaped model with three different colors. Computers are used to predict traffic and change lights accordingly. Imagine a set of people having a heated discussion in a closed room. The conversation can turn into a complete mess if there is no coordinator to look after these people and guide the chatter. In such a situation that isn’t controlled, all we would hear is random shouting and noise, as noone would want to be left behind, so everyone would try to express his/her point of view without consideringwhat the other person has to say. This kind of situation would ultimately lead to total chaos. Now, imagine the same situation taking place on our roads, and simplyreplace the set of people with vehicles. If people were to drive their cars randomly without caring about or consideringother vehicles on the road, it could lead to chaos and may result in accidents; the end result can be catastrophic. Enter traffic lights, which play the role of coordinators on the road. They control the flow of the ever-increasing number of automobiles on the road and they also help in preventing accidents. Let’s take a closer look at how traffic lights have evolved over time. Recommended Video for you: The First Traffic Signal Although the purpose of a traffic signal is to...

The normal function of History [ ] The first automated system for controlling traffic signals was developed by inventors Leonard Casciato and Terminology [ ] In Australia and New Zealand, the terminology is different. A "phase" is a period of time during which a set of traffic movements receive a green signal - equivalent to the concept of a "stage" in UK and USA. One electrical output from the traffic signal controller is called a "signal group" - similar to the UK and USA concept of "phase". Phases [ ] Phases are indications shown to traffic on traffic signal aspects (a single light on a signal head). For example, a green phase gives all traffic from a particular approach the right of way through the junction (bar turning traffic). In the UK, a filter phase allows non-conflicting traffic to make particular turns (normally left or ahead) through a junction. A movement is any path through the junction which vehicles or pedestrians are permitted to take. A movement is conflicting if these paths cross one another. Normally, conflicting movements are not permitted, except for opposed right or left turns (depening on driving side) or, in some jurisdictions, pedestrians and vehicles moving in parallel directions. Stages and periods [ ] A stage is a group of non-conflicting phases which move at the same time. reversion is the stage which the traffic controller will return to if there is no demand. The interstage or intergreen period is the period between the end of a green signa...

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(1877-1963) Who Was Garrett Morgan? With only an elementary school education, Garrett Morgan began his career as a sewing-machine mechanic. He went on to patent several inventions, including an improved sewing machine and traffic signal, a hair-straightening product, and a respiratory device that would later provide the blueprint for WWI gas masks. The inventor died on July 27, 1963, in Cleveland, Ohio. Early Life Born in Paris, Kentucky, on March 4, 1877, Garrett Morgan was the seventh of 11 children. His mother, Elizabeth Reed, was of Indian and African descent, and the daughter of a Baptist minister. His father, Sydney, a formerly enslaved person freed in 1863, was the son of John Hunt Morgan, a Confederate colonel. Morgan's mixed-race heritage would play a part in his business dealings as an adult. When Morgan was in his mid-teens, he moved to Cincinnati, Ohio, to look for work, and found it as a handyman to a wealthy landowner. Although he only completed an elementary school education, Morgan was able to pay for more lessons from a private tutor. But jobs at several sewing-machine factories were to soon capture his imagination and determine his future. Learning the inner workings of the machines and how to fix them, Morgan obtained a patent for an improved sewing machine and opened his own repair business. Morgan's business was a success, and it enabled him to marry a Bavarian woman named Mary Anne Hassek, and establish himself in Cleveland. (He and his wife would hav...