Not all cameras watching the road are for enforcement systems. Most are simply used for monitoring traffic or controlling signal lights.
Enforcement cameras usually need a clear view of a car's rear license plate, so they're often positioned closer to the ground than regular traffic cameras. Many also have a strobe flash system for better lighting.
In the United States, some of the more common systems house their cameras in large, boxy enclosures like these:
Some systems have cameras that look more like regular traffic cameras, but with different positioning and special lighting:
Occasionally mistaken for enforcement cameras, these cameras are used for controlling traffic signals:
Keep in Mind ...
Traffic cameras are usually placed high and pointed so they can see a long row of cars lined up behind a traffic signal or freeway ramp.
Red light cameras photograph vehicles inside the intersection.