Are you ready for four-color traffic lights? The first traffic light, which controlled horse traffic on the Westminster Bridge in London, consisted of semaphore flags and red and green lights. A constable manually operated it. Today, traffic lights consist of red, amber, and green lights, colors agreed upon by an international convention in 1968, and are often controlled by computers and sensors. — Read the rest
The post Are you ready for four-color traffic lights? appeared first on Boing Boing.