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| First Traffic Light in Barcelona, 1929 |
Today, The Grandma has been driving across Barcelona. August is the best month to drive in the city, in fact, the only one because the rest of the year, as a great city, it is very uncomfortable to take the car and it is better to take the public transport.
Since the AntiChrist is managing the city, the transport is being a great problem. The City Hall has reduced important bus lines; travelling by metro is very dangerous because the pick pockets work without any kind of control and with the passive permission of the City Hall's Police and the City has been cut by hundreds of kilometres of bicycle roads with nobody driving by them but disturbing the pedestrians. The city has also a new problem. Hundreds of people are driving by bicycles, skates and roller skates by the sidewalks putting in danger the security and the lives of the pedestrians and by the roads without any respect to the traffic lights.
The city is a chaos by the terrible management of the AntiChrist, who hasn't resolved old problems and has created lots of new ones.
Meanwhile The Grandma was driving and seeing, horrified, the denigration of her wonderful city, she has crossing and emblematic place in the city, the cross between Balmes and Provença Street, the place where was installed the first traffic light in Catalonia. She has also remember Cleveland in Ohio, the city where was installed the first traffic light on a day like today in 1914.
Before driving, The Grandma has studied a new lesson of her Ms. Excel course.
Chapter 9. Inserting and Deleting Items (II) (Spanish Version)
Traffic lights, also known as traffic signals, traffic lamps, traffic semaphore, signal lights, stop lights, robots in South Africa and most of Africa, and traffic control signals in technical parlance, are signalling devices positioned at road intersections, pedestrian crossings, and other locations to control flows of traffic.
The world's first traffic light was short lived. It was a manually operated gas-lit signal installed in London in December 1868. It exploded less than a month after it was implemented, injuring its policeman operator. Traffic control started to seem necessary in the late 1890s and Earnest Sirrine from Chicago patented the first automated traffic control system in 1910. It used the words STOP and PROCEED, although neither word lit up.
Traffic lights alternate the right of way accorded to users by illuminating lamps or LEDs of standard colours (red, amber -yellow-, and green) following a universal colour code. In the typical sequence of colour phases:
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| Traffic Lights Code |
The green light allows traffic to proceed in the direction denoted, if it is safe to do so and there is room on the other side of the intersection.
The amber light warns that the signal is about to change to red. In a number of European countries -among them the United Kingdom- a phase during which red and yellow are displayed together indicates that the signal is about to change to green. Actions required by drivers on a yellow light vary, with some jurisdictions requiring drivers to stop if it is safe to do so, and others allowing drivers to go through the intersection if safe to do so.
A flashing amber indication is a warning signal. In the United Kingdom, a flashing amber light is used only at pelican crossings, in place of the combined red–amber signal, and indicates that drivers may pass if no pedestrians are on the crossing.
The red signal prohibits any traffic from proceeding.
A flashing red indication is treated as a stop sign.
More information: History Hit
In some countries traffic signals will go into a flashing mode if the conflict monitor detects a problem, such as a fault that tries to display green lights to conflicting traffic. The signal may display flashing yellow to the main road and flashing red to the side road, or flashing red in all directions. Flashing operation can also be used during times of day when traffic is light, such as late at night.
Before traffic lights, traffic police controlled the flow of traffic. A well-documented example is that on London Bridge in 1722. Three men were given the task of directing traffic coming in and out of either London or Southwark. Each officer would help direct traffic coming out of Southwark into London and he made sure all traffic stayed on the west end of the bridge. A second officer would direct traffic on the east end of the bridge to control the flow of people leaving London and going into Southwark.
On 9 December 1868, the first non-electric gas-lit traffic lights were installed outside the Houses of Parliament in London to control the traffic in Bridge Street, Great George Street, and Parliament Street.
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| Los Angeles, Barcelona & Washington, D.C. |
They were proposed by the railway engineer J. P. Knight of Nottingham who had adapted this idea from his design of railway signalling system and constructed by the railway signal engineers of Saxby & Farmer. The main reason for the traffic light was that there was an overflow of horse-drawn traffic over Westminster Bridge which forced thousands of pedestrians to walk next to the Houses of Parliament.
The design combined three semaphore arms with red and green gas lamps for night-time use, on a pillar, operated by a police constable. The gas lantern was manually turned by a traffic police officer with a lever at its base so that the appropriate light faced traffic. The signal was 6.7 m high. The light was called the semaphore and had arms that would extend horizontally that commanded drivers to Stop and then the arms would lower to a 45 degrees angle to tell drivers to proceed with Caution. At night a red light would command Stop and a green light would mean use Caution.
Although it was said to be successful at controlling traffic, its operational life was brief. It exploded on 2 January 1869 as a result of a leak in one of the gas lines underneath the pavement and injured the policeman who was operating it.
More information: Artsy
In the first two decades of the 20th century, semaphore traffic signals like the one in London were in use all over the United States with each state having its own design of the device.
One example was from Toledo, Ohio in 1908. The words Stop and Go were in white on a green background and the lights had red and green lenses illuminated by kerosene lamps for night travelers and the arms were 2.4 m above ground. It was controlled by a traffic officer who would blow a whistle before changing the commands on this signal to help alert travelers of the change. The design was also used in Philadelphia and Detroit.
The example in Ohio
was the first time America tried to use a more visible form of traffic
control that evolved the use of semaphore. The device that was used in Ohio was designed based on the use of railroad signals.
In 1912, a traffic
control device was placed on top a tower in Paris at the Rue Montmartre
and Grande Boulevard. This tower signal was manned by a police woman and
she operated a revolving four-sided metal box on top of a glass
showcase where the word Stop was painted in red and the word Go painted in white.
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| William Potts' Detroit Traffic Light |
An electric traffic light was developed in 1912 by Lester Wire, a policeman in Salt Lake City, Utah, who also used red-green lights.
On 5 August 1914, the American Traffic Signal Company installed a traffic signal system on the corner of East 105th Street and Euclid Avenue in Cleveland, Ohio.
It had two colours, red and green, and a buzzer, based on the design of James Hoge, to provide a warning for colour changes. The design by James Hoge allowed police and fire stations to control the signals in case of emergency. The first four-way, three-colour traffic light was created by police officer William Potts in Detroit, Michigan in 1920.
Ashville, Ohio claims to be the home of the oldest working traffic light in the United States, used at an intersection of public roads from 1932 to 1982 when it was moved to a local museum. Many pictures of historical traffic lights appear at a Traffic Signal Trivia page.
More information: The New Wheels
A typical vertical traffic signal has three aspects, or lights, facing the oncoming traffic, red on top, yellow below, and green below that. Generally one aspect is illuminated at a time. In some cases, a fourth aspect, for a turn arrow for example, is below the three lights or aspects in more complicated road traffic intersections.
The simplest traffic light comprises either a single or a pair of coloured aspects that warns any user of the shared right of way of a possible conflict or danger.
-Flashing red: treated as a stop sign. This can also signal the road is closed. In France and the United Kingdom, flashing red mandates absolute stop, at the crossing of a railway line, an airport strip, a swing bridge, or a fire station
-Flashing amber: caution, crossing or road hazard ahead
-Flashing green: varies among jurisdiction. Flashing green can give permission to go straight as well as make a left turn in front of opposing traffic, which is stopped by a steady red light, can indicate the end of a green cycle before the light changes to a solid yellow, or as in British Columbia, Canada, or Mexico City, Mexico indicates the intersection is a pedestrian crosswalk
In the United States, flashing red or amber lights, known as intersection control beacons, are used to reinforce stop signs at intersections.
More information: Road Traffic Signs
Everybody likes driving through scenic, winding roads.
It's hard to find people who like sitting in traffic in cities.
Karl Iagnemma
