Used primarily by State Department's of Transportation (DOT), Piezo Sensors are an axle detection sensor that is installed in the roadway. Most are permanent installations, however many but can be placed temporarily.

Sensors are usually embedded in the lane of travel and can collect count, classification, and Weigh-In-Motion (WIM) data.

Typically a class I sensor is used for weigh-in-motion application while class II sensors are used to collect axle classification data.

Optionally, a non-permanent installation of an encapsulated brass piezo electric axle sensor can be taped temporarily to road surface.

Piezo Sensors are more often used in conjunction with Inductive Loops. They do require sensor testing prior to and after installation and ongoing maintenance.

Keep in mind, that in order to classify (and get SPEED and AXLE data), these permanent classifiers will need both Loop and Piezo sensor inputs.