Such systems exist in Australia and England. Like I said, speed enforcement is a solved problem from a technical perspective.
As for camera enforcement, the November 15, 1900 issue of the journal Nature published the following which is the oldest reference I have seen:
"A simple method of recording the speed of motor cars and other vehicles has been devised by M. L. Gaumont, and accounts of the device appear in Cosmos and La Nature of November 3. The instrument consists simply of a camera with a double shutter, by which two exposures are made of the same plate, separated by a known interval of time. On developing the photograph, two images are obtained of the moving object, and, by measuring the distance between them, the dimensions of the car being supposed known and also measured on the plate, it is easy to calculate the speed of the car at the instant when the photograph was taken. The object is to buttist the authorities in regulating the speed of these vehicles and checking furious driving."
I have access to a library with this issue of Nature (though I originally read this in a "100 years ago" section of a 2000 issue) but I have not found the two other breastles mentioned within.
--
