Traffic lights serve several safety purposes, they direct vehicle traffic, and they help guide pedestrian traffic. Their purpose is to assist with safe traffic movement. They are a huge safety concern when traffic lights are not observed or obeyed.
The first traffic light was used in 1868 in London. The United States first installed a traffic light in the late 1890’s.
As a commercial driver it is important to be aware of traffic control lights, as a result you are trained to look well ahead for them when driving. Hopefully you have heard the term "stale green light". A "stale green light" is a green light that you didn't see change to green and could change to yellow and then red at any moment. When it does change you need to be prepared to stop. Many drivers fall victim to not being prepared to stop and when confronted with a stale green light, the vehicle ahead makes the decision to stop quickly.
As a professional driver, you have to be in control of your vehicle, and that means you can stop safely no matter what. A stale green light is a clear signal to a professional driver, that I need to be prepared to stop, not assume the light will not change, and other traffic will proceed through the intersection. Rather, be prepared to stop when the stale green light becomes a glaring red light, and you can demonstrate you ARE in control of your vehicle and can stop safely. Where safety is concerned, seconds matter!