Piezo sensors are used as axle detectors and primarily used for classification or weigh-in-motion in permanent sites.
Infrared is used where non intrusive technology is needed at an economical price to count remote pedestrian or vehicle traffic.
Inductive Loops are the most used technology for permanent sites. They have been proven to be the most accurate technology for traffic detection available.
Manual or hand held counters are used for intersection and other visual count or classification studies performed by an operator.
Road tube is the most common, flexible and cost effective portable counting or classification solution.