cameras that judge your speed between 2 or more cameras.
It has occured to me that they do not work at night. Travelling to london in the morning I have noticed the infra red is on the cameras. If you shine a light (headlights) into a camera with IR on it just whites out. So i guess they don't work.
On a side note
Have fitted many cctv systems with IR and this is the case. If you want to break into a compound with cctv shine a light into the camera
It has occured to me that they do not work at night. Travelling to london in the morning I have noticed the infra red is on the cameras. If you shine a light (headlights) into a camera with IR on it just whites out. So i guess they don't work.
On a side note
Have fitted many cctv systems with IR and this is the case. If you want to break into a compound with cctv shine a light into the camera