Traffic Light Systems
In our world today, systems play a very vital role in our lives, in the society we live in and in almost everything we do. Systems are defined as a set of detailed methods, procedures and routines created to carry out a specific activity, perform a duty, or solve a problem. It is an organised, purposeful structure that consists of interrelated and interdependent elements such as components, entities, factors, members and parts. These elements continually influence one another directly or indirectly in order to maintain its existence and achieve its goal. So for this week, we’re going to discuss one of the systems that are being used and implemented in our society, the traffic light system. And as we go on, we’re also going to discuss in this article the different types of traffic lights that are currently being used today.
Types of Traffic Lights
Traffic lights are signalling devices positioned at road or junction intersections, pedestrian crossings, and other locations and applications to control the competing flow of traffic. They are installed in almost all of the cities around the world. They assign the right of way to road users by using three standard light colours (red, amber and green), and are usually placed and used at busy intersections to more evenly allocate delay for various users. These three standard colours in traffic lights indicate a specific command. The green light indicates “Go” and it is safe to proceed in the direction denoted. The red light indicates “Stop”, and the amber light indicates “Caution”, either because lights are about to turn green or because lights are about to turn red. Like all other systems, traffic lights have inputs, outputs and feedback mechanisms to maintain an internal steady-state despite a changing external environment. They are also classified into different types namely the incandescent/halogen-based traffic lights, LED traffic lights, Wig Wag Traffic Light System, and Walking Man Traffic Lights.
Incandescent/Halogen-based Traffic Lights – This traffic light is the traditional type which uses incandescent or halogen bulbs. Many people eventually switched from this type of traffic light to another such as LED-based traffic lights because of its low efficiency light output and a single point of failure or filament burnout.
LED Traffic Lights – This type of traffic light lamps are using light-emitting diodes as an alternative to the traditional incandescent or halogen light bulbs. LED traffic lights are composed of an array of LED bulbs arranged in diverse patterns, unlike the incandescent-based traffic lights which use a single large bulb. These multiple LED bulbs when viewed from a distance, appears as a continuous light source. Most consumers prefer this type of traffic light because of its numerous advantages such as greater energy efficiency, capability to be solar-powered, much longer lifetime between replacements, bulbs will still operate even if some of the LED bulbs in the array fail, brighter illumination with better contrast against direct sunlight, capability to display multiple colours and patterns from the same lamp, and much faster switching. Instead of sudden burn-out like incandescent-based lights, LEDs start to gradually dim when they wear out which indicates the need for replacement.
Wig Wag Traffic Light – Wig Wag Traffic Lights are more noticeable than simple traffic lights. They are generally used at level and bridge crossings, and emergency services station such as fire/ambulance stations where there is a need to stop ordinary traffic flow in order to enable emergency vehicles to exit the station. They can also be easily incorporated into a Traffic Management System to control a facility or site. They are also extremely useful especially in factories where the clutter of other signs may get a red traffic light goes unnoticed and in instances where there may be a need to stop all traffic while a vehicle needs to emerge or reverse out of a blind spot.
Walking Man Traffic Lights – Walking Man Traffic Lights are usually LED based indicators used for pedestrian flow at traffic management stations. A steady “standing man” or “don’t walk” signal is an indication that a pedestrian cannot enter the street in that signal’s direction, while a steady “walking man” or “walk signal” indicates that pedestrians can start crossing the street toward that signal.
As we look at our society today, busy people are going to and fro almost every hour of the day. Imagine what cities would look like if traffic light systems didn’t exist. Perhaps chaos and confusion may arise on our streets. Even if a traffic enforcer is present, the timing of every stop and go will not be as easy as it seems, as everyone is subject to fatigue, confusion and errors.