Traffic Light

Traffic Light

Traffic lights, also known as traffic signals, traffic lamps, signal lights, robots and semaphores., are signalling devices positioned at or near road intersections, pedestrian crossings and other locations to control competing flows of traffic. Traffic lights were first installed in 1868 in London, United Kingdom; now used in almost every city of the world. Traffic lights alternate the right of way accorded to road users by displaying lights of a standard color (red, yellow/amber, and green) following a universal color code (and a precise sequence to enable comprehension by those who are color blind).

In the typical sequence of color phases:

  • Illumination of the green light allows traffic to proceed in the direction denoted, if it is safe to do so
  • Illumination of the orange/amber light denoting prepare to stop short of the intersection, if it is safe to do so
  • Illumination of the red signal prohibits any traffic from proceeding

Usually, the red light contains some orange in its hue, and the green light contains some blue, said to be for the benefit of people with red-green color blindness.

Read more about Traffic LightHistory, Lights For Public Transport, Turning Signals and Rules, Lane Control, Special Provisions, Dummy Lights, Implementation, US Department of Transportation Manual of Uniform Traffic Control Devices, Legal Implications, In Other Contexts, Gallery

Other articles related to "traffic light, traffic lights":

Traffic Light - Gallery
... An LED traffic light Temporary LED traffic lights with sensor in Australia Temporary traffic light in the United Kingdom Traffic light on a small intersection in Maryland ...
J. S. Pridemore - Legacy
... the city of Hamlin, West Virginia, being unable to afford its own traffic light, petitioned Pridemore to purchase one for them ... Pridemore happily purchased the traffic light, but entirely failed to obey it ... Upon being ticketed by local police, Pridemore immediately had the traffic light removed until the ticket was dismissed ...
Traffic Light Coalition
... Traffic light coalition (German Ampelkoalition) is a term originating in German politics where it describes a coalition of the Social Democratic Party (SPD), the Free ... red, yellow, and green, resemble the normal colour sequence of a traffic light ...
County Road 17 (Elkhart County, Indiana) - Route Description
... At CR 38, the route has a traffic light followed by a traffic light at State Road 119 (SR 119) ... The highway has a traffic light at CR 28, CR 28 links CR 17 and US 33 ... After CR 28 is a traffic light with Rieth Boulevard, which also provides access to US 33 ...
Traffic Light Rating System - Product Labelling - Food
... Food sold prepacked may be labelled with a traffic light label showing at a glance the proportions of fat, saturated fats, sugar, and salt using ... The use of traffic light labelling is supported by many physician groups including the British Medical Association and welcomed by consumers. 6.3g more than 6.3g Salt less than 0.3g between 0.3g and 1.5g more than 1.5g Currently the traffic light label is used in some European countries on a voluntary basis ...

Famous quotes containing the words light and/or traffic:

    The light of memory, or rather the light that memory lends to things, is the palest light of all.... I am not quite sure whether I am dreaming or remembering, whether I have lived my life or dreamed it. Just as dreams do, memory makes me profoundly aware of the unreality, the evanescence of the world, a fleeting image in the moving water.
    Eugène Ionesco (b. 1912)

    Cry;—and upon thy so sore loss
    Shall shine the traffic of Jacob’s ladder
    Pitched betwixt Heaven and Charing Cross.
    Francis Thompson (1859–1907)