Gnu: In Philadelphia, PA, U.S., they've just installed some of these cameras on Roosevelt Boulevard to catch people who drive through red lights. Thus far they've photographed about 9 an hour, but the authorities aren't issuing fines yet. When they do, their hope is that violations will be reduced; I suspect that they will simply generate violations of the non-payment-of-fines sort.

About traffic "roundabouts" ("circles" in the Philly area, a.k.a. "rotaries" in parts of New England, U.S.): In southern New Jersey, they have REMOVED several circles to improve traffic flow on state highways in the more metropolitan areas (such as Route 73 in Marlton). Also, left turns are prohibited on a lot of crossroads there, and one must make an exit to the right onto a "jughandle" that loops around and allows one to merge onto the cross-street (NJ's alternative to widening the roads to allow for a left-turn lane).