0
Several answers But 1 interesting one .... They change via metal sensors buried in the road that detact when a car is above them. See the (usually) dark tarmac diamond shapes in the road. Once metal is detected (ie car). They then decide if they should change or not. IE due to prevailing conditions ie traffic crossing the intersection or the presence of pedestrian crossing lights giving each a priority in turn.
Wiki User
∙ 16y ago
Add your answer:
Earn +20 pts
When are flashing red and yellow lights used to control some traffic intersections?
Flashing traffic lights are used when the control system is not functioning properly, or when there is very low level traffic (to the point that lights become unnecessary).
What counties in Wisconsin have no traffic lights?
forest
What are the Traffic lights called in American English?
They are called traffic lights or traffic signals. -------------------------------------------------------- *** 2nd Answerer Says: Some parts of the country call them stoplights (as opposed to go-lights or caution-lights) and there is a variation called "blinking lights". "Blinking lights can be blinking red in all four directions to designate a four-way stop or full-stop in two directions & cautionary slow-down (blinking yellow) the other two directions.
How smart are crows?
crows are very smart. They can even understand traffic lights!
Has DJ Tiesto died?
No, he actually just released some new music. The songs Traffic and Red Lights are available.
The average person will spend over 2 in their lifetime waiting for traffic lights to change?
The average person will spend over 2 weeks in their lifetime waiting for traffic lights to change.
What change the traffic lights beside the pedestrians button?
A computer that the trafic lights are conected through.
What is the light on top of traffic lights that cops can turn on?
Emergency vehicles carry a transponder that transmits a radio signal to change the traffic lights to green for them.
What city has traffic lights shaped like Hershey's kisses?
I don't know about traffic lights, but Hershey, Pennsylvania has street lights shaped like Hershey's Kisses.
Does flashing your headlights at a red traffic signal make it change to green?
No, Flashing your headlight's will have no effect on a traffic signal. The reason a traffic signal changes for emergency vehicles that have the lights flashing, is, they have a special transmitter that tells the light to change. This transmitter is connected to the emergency lights so it comes on when the lights are used.
Can black cabs change traffic lights?
In London, black cabs are detected in the same way as any other vehicle, so they are given no preference at traffic lights.
What can one do with a used car alarm?
Change traffic lights check google.
What are the disadvantages of the traffic lights?
* The disadvantages of traffic lights r * Traffic lights can cause a chaos on the roads.* Also cause a huge traffic
What is time requirement for traffic lights change from green to yellow?
It depends on what time of day it is.
How did the traffic light change the world since 1920?
It did change the wrold alot because we didnt have traffic lights and there would be alot of accidents and when they invented the traffic light they could get around easier and it made it safer
What is the circuit diagram of the traffic lights?
It is not really a circuit, traffic lights in todays world are controlled by programable logic controllers or a plc. There are rungs of logic to control the changing of the lights which are known as the inputs and outputs where the voltage is controlled to change the lights from red to yellow and green.
Did traffic lights change. i seem to remember them being green on top and red on the bottom.?
The lights are still in this order: RED YELLOW GREEN
