What type of loop detector is most commonly used in California?

Single loop detectors are widely recognized as the most commonly utilized type in California due to their simplicity and effectiveness in vehicle detection at traffic signals. This type of detector consists of a single loop of wire that is embedded in the pavement, creating an electromagnetic field. When a vehicle passes over the loop, it alters the inductance of the loop, which the traffic signal control system can then detect.

The advantages of single loop detectors include their relatively low installation cost and ease of maintenance. They are often sufficient for detecting vehicle presence and can effectively manage traffic flow at intersections, making them a preferred choice in many situations.

While other types of loop detectors do exist, single loop detectors continue to dominate due to their efficiency and the straightforward nature of their operation, making them ideal for various traffic control applications. This practical approach to vehicle detection aligns well with California's traffic management strategies, reinforcing the choice for single loops over more complex or costly alternatives.