Palisades, District of Columbia Speed Traps
The camera (and flash) is located in a metal box a short distance east (inbound) of Arizona Avenue. The giveaway is a series of white lines across the middle of the parkway. Brand new (January 2012). the camera is just off the roadway on the hill side of the parkway (not the canal side).
Cameras from Arizona to the Reservoir consistently fine motorists for speeds less than 5 mph over the limit. Flow of traffic is much faster than this; it can be unsafe to travel that slowly during rush hour. Which motorists get fined seem entirely random.