Photo Credit: Karl Jansen
This is your typical traffic light in the USA: red on the top, yellow in the middle, and green on the bottom. The four individual signals are supported by the cantilevered mast arm. Traffic lights are seen all over the world, and help traffic flow safely in multiple directions. The design of the signal processing is done after a complete and thorough investigation of existing traffic flow is completed by a traffic engineer. The traffic engineer uses this information to formulate the optimal combination of light sequence order and timing, so that everybody gets along their way in good time and safely.