I work on traffic surveys and footpath surveys and I know that there are a lot of counting devices alongside roads and paths, simply to measure the flows of vehicles or people, which don't have any labels on them to indicate their function. (That's partly because they can get mistaken for speed cameras and then be vandalised).
Although I've not seen that particular design before, I'm wondering whether the device projects a radar beam to sense traffic movements.
Sorry, we can't find any related questions. Try using the search bar at the top of the page to search for some keywords, or choose a topic and submit your own question.