Vehicle Loop Detection
More sophisticated control systems use electronic loop detectors which are sensors buried in the pavement and/or mounted over the roadway (video, acoustic) to detect the presence of vehicles at the intersection and even estimate the speed, length, weight of vehicles and the distance between them. The loop detectors typically work in the same fashion as metal detectors and are NOT immune to degradation associated with transients and/or higher-voltage events like lightning.
SURGE PROTECTION PRODUCTS
TOOLS AND DOCUMENTS
A Guide to Surge Protection and Filtering