state the procedure of changing the on and off timings of traffic signals
Answers
Traffic lights are normally computer controlled, to coordinate the traffic flow at intersection of roads. They are programmed in such a way that traffic on the road with maximum flow is allowed to pass for a longer time, than the traffic on roads with lesser traffic. An algorithm is usually set, based on volume of traffic over a period of time.
At times, traffic lights are also controlled manually by the Traffic Police.
The traffic signals timers have fixed time period to switch traffic between the different directions. This involves determining the sequence of operation. The algorithm is represented by computed control functions depending on the number of vehicles queued and demanding service at the intersection,information that modern detecting equipment can supply to a central computer. There are some algorithms which computes the traffic flow and traffic signals/lights in real time. There are some algorithms that can sense the traffic in all directions and quickly give the green signal to the low priority direction if traffic is light in high priority direction. Actually, it depends on the method of control because fixed time has no algorithm.
Hope it helps!