Small cameras around Burchetts Green area

[sad61t]

Noticed some small cameras and large data boxes attached to road signs in the roads near the A404 Burchetts Green roundabout. Anyone got an idea what they're being used for? They're not speed cameras, but smaller and aimed towards number plates. Thinking some kind of ANPR used to monitor traffic flow ready for some new traffic management scheme around Bisham Abbey and Burchetts Green.