They do.....

But infrared.

Quote:

Functionally, they are also quite different. Gatso's typically use radar to detect the speed and a visible-light flash to illuminate the scene (from behind) for a photograph to be taken. A Truvelo uses buried induction loops in the road to detect a vehicles speed and an invisible infra-red flash to illuminate the scene (from the front) for a photograph. A photo from a Truvelo includes the drivers face, unlike a Gatso photo and thus identifies the driver as well as the vehicle.

All of this makes a big difference because to avoid having your photo taken (if you see the camera), you need to be travelling below the limit as you cross the strips 25metres in front of a Truvelo camera, opposed to 10-20metres behind a Gatso!

End quote.

Posted By: Johnny Comecardiff, May 29, 14:20:27