How Are Traffic Lights Made?

Traffic lights are illuminated hardware used to control vehicle and pedestrian traffic. Traffic lights shows the drivers when to stop, when to slow down or when to move. Therefore, it helps to prevent traffic jam and improve the safety of drivers and pedestrians.

A modern traffic light consists of signal module, housing, and traffic signal pole.

Signal Module

LED light sources which have high efficiency, long service life is using in today’s traffic lights. The first stage of producing traffic light is LED choice. Related international standards and performance necessities are considered separately for Red, Yellow and Green LED. Light outputs of LEDs are significantly important for signal module performance and visibility. A printed circuit board is designed in order to get a large number of LEDs operates together. LEDs installed on circuit board and the circuit board fixed to the base of signal module.

In order to operate the LEDs, a special voltage range and a constant current is needed. Power sources called LED drivers are used to convert the electric current coming from the traffic control device to suitable voltage and current for LEDs. Power source located in signal module.

The body of signal module is like hemisphere. Signal housing is made of polycarbonate. The outside diameter can be changed as 100 mm, 200 mm, 300 mm according to the usage area. The inner surface of the body is painted into black to prevent glare. A Fresnel lens and a front shell mounted to the open surface of housing to collect the light and emit the light in the form of parallel rays. A rubber joint placed between front shell and housing to ensure the sealing.

Signal Housing

Signal housing is used to connect signal modules, ensure them operating together and protect the electrical connections. Signal housing consist of separate rooms for each color. Signal modules inside the housing can be changed separately. Therefore, in case of a failure, instead of changing the housing, you can change malfunctioned signal module. Housing sizes must be suitable for signal modules. Each part of the housing has a visor to ensure the visibility of signal modules even under the bright sunlight. In this way, the sun rays coming from the sky are prevented from reaching the front surface of the signal module and glaring. Signal housing is made of polycarbonate like signal module.

Signaling Pole

Signaling poles are used to mount signal heads to suitable height and places that the drivers and pedestrians can easily see. Signaling poles can be straight or with arm according to the usage area and intended purpose. Signaling poles are made of galvanized steel to ensure corrosion resistance and strength at outside conditions.

While the traffic lights that used in the past had 100 W power consumption, today the power consumption of many traffic light is less than 10 W. Less power consumption and high performance is aimed day by day in traffic signalization. That makes the traffic lights more complex and pushes the producers to do r&d activities.