You can find traffic light controller devices at road intersections. They're used to manage vehicle movement on the road. Every traffic light consists of three lamps—red, yellow, and green. These colors have the following meaning:
Red: Drivers must stop their vehicle
Yellow: Drivers should prepare to start to drive or start to stop
Green: Drivers must drive their vehicle
A sample traffic light can be seen in the following figure:
These traffic lights are usually placed at the corner of a road intersection, as shown in the following diagram. You can see them on your left- or right-hand side. Sometimes, they're shown over the top of your vehicle:
In general, there can be two, three, four or n road intersections. We know that a traffic light needs three lamps, so to implement n road intersections, you need at least 3n lamps. You may need walking and do not work lamps. Some traffic road intersections can be seen in the following figure:
In this chapter, I will...
