England has changed a lot in the last 20 years regarding speed traps. They used to never pull you over unless you were driving unsafely. And then they'd give you a tongue lashing for it. Today the intolerance for speeding has become an institutionalized norm where 3 mph over the limit is enough to get you a fine. Auto manufacturers for the British market are including automatic speed limiters (ASLs) as accessories that prevent the car from exceeding a set speed. The Brits have pioneered the automation of modern speed traps and are importing that technology into the U.S., specifically the state of New Mexico, who has just undergone a pilot project that ended, I believe, this July. There are about 8,000 such sites in England. About half are in fixed locations, the other half are moved randomly.
In another variation, the state of Minnesota has zones where enforcement is not uniform with state norms. State-wide, if the the posted speed is 55, then you can usually get away with a speed under 65 without a ticket. In these special zones, anything exceeding 55 can get you a ticket. Recently, a company I worked for had the state of Iowa for a client. Iowa was implementing a similar program, and they even showed us how much revenue they expected to get from the program, and what specific new programs would be funded by it. The psychology of this is very unfortunate because drivers are used to driving 5 to 10 mph over the posted limit. That expectation is true for most of the state, and in fact, not travelling according to this norm constitutes a safety hazard. Of course, the police say that it's in the name of public safety.
By the way, you've heard the phrase "speed kills"? Not as true as you've been led to believe. Alcohol and driving kills, but speeding on roads like interstates is actually a pretty safe practice.
