Traffic Lights are controlled by a microproccessor system. Give 2 methods of automatic collection of traffic?

i how can a traffic light collect the traffic data.Traffic Lights are controlled by a microproccessor system. Give 2 methods of automatic collection of traffic?
In-pavement sensors used to trigger left turn lights can be used to count vehicles passing over.





Two of these sensors in the same lane spaced a short distance apart can be used to determine traffic speed.





A in-pavement sensor placed beyond the stop line, when logically AND'd with a signal indicating a red light can count number of red light runners.Traffic Lights are controlled by a microproccessor system. Give 2 methods of automatic collection of traffic?
When i was in college I had to program and build a signal light system on a protoboard with timers and leds. It was fun, but very frustrating to write the program. It was much easier using the Program Logic Controller instead.