What are these devices above traffic lights?

I've researched, and some places say they are offline devices that just change the traffic lights and help with flow replacing in ground sensors. Other places say these are traffic monitoring that are live and viewed from central location. Other say these are red light cameras taking video/pictures and recording.

[https://imguh.com/image/nmUP9](https://imguh.com/image/nmUP9)

What are these devices?

devices privacy traffic