Traffic Lights - Transport Department

Traffic lights control movements of all road users. They tell drivers and pedestrians when to stop or go. Traffic lights for drivers and cyclists are illustrated on this and the following two pages. Traffic lights for pedestrians are illustrated on page 17.

For more led traffic signal lightinformation, please contact us. We will provide professional answers.

In the majority of cases, as well as the main traffic lights at the 'Stop' line, there are duplicate traffic lights known as secondary traffic lights. They are usually located on the opposite side of the junction (or crossing), but are sometimes placed on the same side of the junction. If the main traffic light fails, for example, a green lamp fails, you must obey the secondary traffic light as if it were the main traffic light. Once clear of the 'Stop' line you should continue with care, without reference to the traffic lights.

 

Traffic signs may also be used with traffic lights to qualify the meaning of the green light such as banning a turning movement or instructing traffic that it must move in a certain direction.

For some signalised junctions with right-turn pockets (see page 75), an indicative right-turn green arrow may be added.

When the full green light is on and the right-turn arrow is off, the right-turners can proceed into the pocket to wait for a safe gap in the opposing traffic stream and turn right when it is safe to do so. Other traffic movements are allowed to proceed.

When the right-turn arrow is on as well, it indicates the opposing traffic is stopped by red traffic
light and you can turn right if safe to do so.

If movement is allowed only in one direction, a green arrow pointing in that direction may replace the full green light. Signs are often used with these signals to indicate this permitted movement direction. A green arrow may light up even though the red light is still showing. This means you can go in the direction shown by the arrow if it is safe to do so, whatever the other lights may be showing. At some junctions, different traffic lanes may have separate traffic lights. You should only obey the traffic lights that apply to your lane.

Intermittent red light warning signals (wig-wag)

When red lights are flashing alternately, all approaching vehicles must stop, until both red lights have stopped flashing. These lights are used at places where traffic is only stopped infrequently - for example at fire station exits.

Traffic Lights

Have you ever wondered what hardware sits on top of a traffic light/traffic signal?

It is usually pretty obvious what hangs down from a traffic signal mast arm pole – a traffic signal. However, the gadgets on top of the pole can sometimes throw us a loop.

Are the cameras on top designed to catch red-light runners? Or is it the government recording and tracking our every little move?

All conspiracies aside, the real answer is that those gadgets you see on top of traffic lights almost always have a purpose, and today, we will help you understand what you might be looking at.

What sits on top of traffic lights?

You might be asking, “What are those little things on top of street lights at an intersection?”

Are you interested in learning more about traffic light countdown timer? Contact us today to secure an expert consultation!

Explore more:
Advantages and Disadvantages of the Bridge Rectifier
What are the disadvantages of infrared touch screen?

To help you understand the answer to that perplexing question, it is vital to first understand what makes a traffic light function properly in the first place!

Many traffic lights operate on a networked system that is managed by a city’s TMC (Traffic Management Center). Designed to make sure traffic volume and pedestrian movement flow smoothly, traffic signals are vital to keep in a constant state of safe movement.

While most motorists just view traffic signals as a way to help cars and pedestrians cross an intersection safely (and that is true) they have a vital role in highly populated cities by helping mitigate traffic issues.

Those factors include:

• Emergency response vehicles and response times
• Drivers, pedestrians, cyclists
• Public transit routes
• Timing & Efficiency (think green energy)

Keeping in mind these factors, below are a few of the gadgets you might see on top of a traffic light.

1. Cameras & Sensors

Most of the gadgets on top of a traffic light are usually cameras. The video detection cameras are not designed to record you, but instead to detect traffic (by the way, flashing your lights doesn’t change the light!)

The drone-looking cameras that hang from a traffic light are actually “Pan & Tilt” cameras which allow traffic engineers to see an entire intersection corridor. Emergency vehicle detection sensors are also commonly visible on top of an intersection.

If you happen to see anything odd, like a strange box or super long antenna, these can be traffic signal preemption systems at work! Put another way, they are sensors and wireless devices used for traffic safety and helping traffic engineers.

All in all, you shouldn’t be alarmed if you see a camera and while you might think the camera on top of a traffic signal is a red-light camera, they’re usually not.

2. First Responder Gadgets

The tiny black device with the light either on the end or next to it is usually an infrared preemption device. These small gadgets are used to turn lights green for emergency vehicles. The infrared devices have a partner device located on the emergency vehicle. Once the vehicle operator comes within range of the traffic signal, the infrared light system sends a signal to the device on the traffic signal, turning the light green.

Fortunately, newer technology exists that negates the need for such hardware on top of the signal mast in order to give green lights to first responders.

Another device you may frequently see on a traffic light is a small blue light on the backside of a traffic light pole. These lights aren’t just for decoration! In fact, these lights aid police in identifying dangerous red-light runners. When the light is illuminated it signals to police officers that the light in that direction is red.

3. Other Gadgets

Crosswalk signals are something that is typically reserved for the side of a street light pole, but in rare instances, you might see signals on top of traffic light intersections.

Pedestrian detection sensors and equipment might find their way on top of a traffic light. A really unique feature cities are moving to, is the delayed timing of a green light if a pedestrian is moving slower than usual through an intersection!

Other possible answers to your inquisitive nature could be that what you see is a device that is used to collect data for traffic management purposes. With many cities moving to artificial intelligence and cloud-based traffic management systems, most of the gadgets you see are being utilized to help with traffic.

Rest assured – you don’t need to worry, all the things you see are not some alien or government contraption with an ulterior motive!

To learn more about LYT’s cloud-based traffic management products, request a demo here!

Want more information on radar speed signs? Feel free to contact us.