Traffic lights, also known as traffic signals, traffic lamps, signal lights, stop lights and robots, and also known technically as traffic control signals are signalling devices positioned at road intersections, pedestrian crossings and other locations to control competing flows of traffic. The first manually operated gas lit traffic light was installed in 1868 in London, albeit it was shortlived due to explosion. The first safe, automatic electric traffic lights were installed in the United States starting in the late 1890′s.
Traffic lights alternate the right of way accorded to road users by displaying lights of a standard color (red, yellow, and green) following a universal color code. In the typical sequence of color phases:
This video is targeted to blind users.
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Post time: Jun-19-2017