Round (or square) loops are usually for presence detection only. It detects when a vehicle is over it...or passing over it as it drives by. Rectangular loops do that as well, but also have the option for V+O (Vehicle and Occupancy) control to adjust the coordination plans for nearby intersections when several cars are waiting in a queue
This is where video detection is your friend...since you can design whatever size "loop" you want since its all virtual!
This is where video detection is your friend...since you can design whatever size "loop" you want since its all virtual!