How do pelican crossings work?

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In summary, a pelican crossing is a pedestrian-controlled traffic signal that is found in the UK. The green man is generated when the pedestrian presses the button, and the driver sees a flashing amber between red and green.
  • #1
lavster
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can anyone tell me how a pelican crossing works? I've found loads on web about how traffic lights in generalbut I am interested in how the green man is generated one the pedestrian presses the button. is it a capacitor?

thanks :)
 
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  • #2
They run on mains power.
The button starts a cycle of turning on the amber, then red lights for the drivers and the green light for pedestrians. You could do it with a simple 555timer and a counter but I suspect for reliability and to allow more complicated schemes, eg shorter delays at busier times, you would use a microcontroller.
 
  • #3
What the hell is a 'pelican crossing'? :confused:
Is this another instance of Florida weirdness?
 
  • #4
Danger said:
What the hell is a 'pelican crossing'? :confused:
Is this another instance of Florida weirdness?
It's the standard name in the UK for pedestrian-controlled traffic signals.

Pelican crossing.
 
  • #5
Thanks for the clarification, Dr. Greg. That's some mighty weird terminology.
Here in Canada, a pedestrian crosswalk with a button has minimal effect. It causes the 'walk' light to illuminate upon the next normally scheduled switch of the main traffic lights. That points out to drivers the pedestrian right-of-way, which in normal traffic affects only someone turning onto the street in question (since someone already on that street is held up by the main lights). That right-of-way exists at all times, whether or not the intersection is lighted or even marked, but the light makes it more noteworthy.
 
  • #6
There are also midblock crossings that aren't associated with intersections, and are activated on demand by pedestrians.
 
  • #7
jtbell said:
There are also midblock crossings that aren't associated with intersections, and are activated on demand by pedestrians.

True. That's a relatively new development in my area. There are none in my town, but Calgary has quite a few.
 
  • #8
jtbell said:
There are also midblock crossings that aren't associated with intersections, and are activated on demand by pedestrians.
To clarify, that is what we call a "pelican crossing" in the UK. We have lots of them (usually in places a considerable distance from a light-controlled intersection). The lights at an intersection are just called "traffic lights" regardless of whether there's a pedestrian button or not.

One of the reasons "pelicans" have a special name is because the sequence of lights that the driver sees is slightly different: between red & green there is a flashing amber which means "give way to pedestrians, but otherwise, go".
 
  • #9
I guess that I won't be renting a car if I ever visit England. Staying on the wrong side of the road would take all of my concentration, never mind trying to learn your signal system. :rolleyes:
 

Related to How do pelican crossings work?

1. How do pelican crossings know when to change?

Pelican crossings use a combination of sensors, including pressure sensors and cameras, to detect when a pedestrian is waiting to cross. This information is then relayed to a control box, which decides when to change the traffic signals.

2. How do pelican crossings communicate with drivers?

Pelican crossings use traffic signals and road markings to communicate with drivers. When a pedestrian presses the button to cross, the traffic signal changes to red, indicating to drivers that they must stop.

3. How do pelican crossings ensure the safety of pedestrians?

Pelican crossings have a number of safety features, including a flashing amber light to warn drivers that the crossing is about to change, and a pedestrian island in the middle of the road to provide a safe place for pedestrians to wait.

4. How do pelican crossings differ from other types of crossings?

Pelican crossings are different from other types of crossings, such as zebra crossings, because they use a combination of traffic signals and road markings to control the flow of traffic. They also have a dedicated button for pedestrians to press to activate the crossing.

5. How do pelican crossings benefit traffic flow?

Pelican crossings help to improve traffic flow by providing a designated time for pedestrians to cross, which reduces the likelihood of them crossing at a dangerous time. This also allows traffic to flow more smoothly when there are no pedestrians waiting to cross.

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