does anyone know how a traffic signal works ?
470277
At an intersection, traffic lights for each direction are connected together and coordinated with each other based on specific criteria inputed by a specialist.  These criteria are accessed at and located in a "traffic cabinet" or metal box that is located near the intersection.  The specific criteria consists of such things as how many cars need to be waiting before the light changes, the time that a car waits before the light changes, the amount of time given for pedestrians to clear the crosswalk, etc.\n\nA car can be sensed by "loops" in the pavement or by cameras mounted on the signal mast arms, in the air.  Pedestrians can be sensed when they push a button, by camera, or automatically included in the traffic signal "cycle" or pattern of lights and timing.
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On 10 December 1868, the first traffic lights were installed outside the British Houses of Parliament in London, by the railway engineer J.P. Knight. They resembled railway signals of the time, with semaphore arms and red and green gas lamps for night use. The gas lantern was turned with a lever at its base so that the appropriate light faced traffic. Unfortunately, it exploded on 2 January 1869, injuring the policeman who was operating it.\n\nOptics and Lighting\nIn the mid 1990s, cost-effective traffic light lamps using light-emitting diodes (LEDs) were developed; prior to this date traffic lights were designed using incandescent or halogen light bulbs. Unlike the incandescent-based lamps, which use a single large bulb, the LED-based lamps consist of an array of LED elements, arranged in various patterns. When viewed from a distance, the array appears as a continuous light source.\n\nLED-based lamps have numerous advantages over incandescent lamps; among them are:\n\n    * Much greater energy efficiency\n    * Much longer lifetime between replacement, measured in years rather than months. Some of the longer lifetime is due to the fact that the light is an array which allows the light to be used even if some of the LEDs in the array are dead.\n    * Brighter illumination with better contrast even in direct sunlight.\n    * The ability to display multiple colors and patterns from the same lamp. Individual LED elements can be enabled or disabled, and different color LEDs can be mixed in the same lamp.\n    * Much faster switching.\n    * Instead of a sudden burn-out like incandescent-based lights, LEDs start to gradually dim out when they're past their prime, allowing transportation maintenance departments to be warned well in advance as to when to change the light.\n\nThe operational expenses of LED-based signals are far lower than equivalent incandescent-based lights. As a result, most new traffic light deployments in the United States, Canada and elsewhere have been implemented using LED-based lamps; in addition many existing deployments of incandescent traffic lights are being replaced. Many of the more exotic traffic signals discussed on this page would not be possible to construct without using LED technology. However, color-changing LEDs are in their infancy and may surpass the multi-color array technology.\n\nIn some areas, LED-based signals have been fitted (or retrofitted) with special Fresnel lenses and/or diffusers to limit the line of sight to a single lane. These signals typically have a "projector"-like visibility; and maintain an intentionally limited range of view.
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In most states they go with traffic because they are considered a vehicle, they have to obey stop signs and traffic signals and yield for pedestrians. You might even get a traffic ticket if you ride on the sidewalk and not in the street.
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no u will be turning into oncomin traffic. Most places now u cant even turn left on a green light u must wait for the green arrow. A right turn on red u can only if nothing is posted and u yield first.
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If you really want to know, it would have to be a stop sign.\n\n(Don't worry, your not a loser.  I am.)
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Not sure what your question is, but my great-uncle, who worked for Bell Laboratories, was one of the electrical engineers who developed the moving sequence of lights for that sign. You go, Uncle Arthur!
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it will just depend on thier assignment,  some officers are assigned to do traffic all shift ( nothing but traffic)  \n\nIn most traffic/patrol units most officers are too busy rushing from call to call  In Atlanta for example most officers have one to two calls waiting when they get done with the one they are on, and only do traffic stop in the most serious cases.\n\nIn our department I normally did about 3 stops a shift, and normally only ticketed one ( gave warnings normally)\n\nmost stops were normally looking for something else
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UNFORTUNATELY IT WORKS, IS DIRECTLY CONNECTED WITH A SPEED SENSOR CONNECT TO THE OFFICER'S VEHICLE.  IT WORKS APPROACHING OR ON-COMING.  ANTENNA'S ON VEHICLES ARE DIFFERENT BUT DOWN HERE WE USE A ANTENNA WHICH APPEARS TO BE A SPOTLIGHT HOOKED OVER THE TOP OF THE WINDOW GLASS.  IT MAY BE AIMED UP OR DOWN THE ROAD.\n\nWORKS AS LONG AS THE VEHICLE IS IN SIGHT!\n\nDRIVE CAREFUL HEAR !
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The resolution vector of the two attached cables has to equal the opposite of the traffic light's downward vector of 980N.  Draw the two vectors head to tail.  They will make a 70 degree angle. Depending on which vector you move, the angle at the top where the resultant starts will be 50 or 40, and at the bottom will be 60 or 30 degrees.  Use the Law of Sines to find the magnitude (tension) of each vector (cable).  \n\nsin 70 / 980 = sin 50 / x where x is the cable at 30 degrees; x = 798.9N\n\nsin 70/980 = sin 60 / y where y is 40 degree cable:\nx = 903.2 N\n\nIs that what you got?
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Hi again Anna. The best way to explain this is to draw it, but absent that, just imagine a circuit where one "loop" goes to the bulb while the other completes the circuit. In this "parallel" circuit, even if the pathway to the bulb is cut off (as when the bulb blows out), the other loop is still closed, and so the circuit is complete and the circuit is intact.\n\nBut when a series circuit is cut, there is no alternative, loop, pathway. That's it. \n\nImagine driving on a highway and suddenly there is an accident. If you can take the exit and make a detour (a loop around the accident) you can still get to your destination easily. But if that's the only way to your destination, your trip ends there. Having a detour on a highway is like having parallel circuits in electricity.
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it seriously can't be that difficult....\n\n\nthe red octagon tells you to cease the car's movement.  the yellow light signifies a warning of traffic stoppage.  drive the speed limit as posted.  stay on the right side of the road.  don't piss off the cops.
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Check http://www.howstuffworks.com\nUltimate guide!
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The 'How Stuff Works' website has a really good explanation.  You can find it at http://home.howstuffworks.com/question420.htm
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possible openings to explore might include the timing of the yellow light, there have cases where it has been reset to less time which makes violations almost unavoidable. any traffic engineer can tell you what is a proper setting for the yellow but anything under 3 seconds could be considered a trap. a second thing might be the amout of time that passed between the violation and you recieving notice of it since too long a time could prevent you from mounting a defence simply because you no longer remember what happened. a third defence might be a claim of necessity because of the actions of another such as a tailgater behind you.
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It is illegal in the state of Washington to drive through a red light.  The yellow light is given to warn you the light will change soon.  It is the drivers responsibility to make sure they are through the intersection before the light turn red.  However, high traffic volumes often make it nearly impossible to turn left.  Sometimes people are forced to wait until traffic clears after the light turns red.  \n\nTo answer your question:  It is illegal, but everyone does it.  It happens so offten it is hard for the police to enforce.
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Check out Detroit's Traffic Engineering Department\n\nhttp://www.ci.detroit.mi.us/dpw/services/Traffic_Eng.htm
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A rear brake signal, which is to be installed in the car when I buy one.