So Who Will Get All The Tickets?B. A. Lefeve. "Speed Habits Observed on a Rural Highway." Highway Research Board Proceedings, 33 (1954), Abstract.
"An average driver, i.e. a driver whose average speed is equal to the overall average, can be expected to exceed the 85-percentile speed about 11 percent of the time."
The 85th percentile (so the government says) is used as the camera trigger speed. If you are an average driver, you might want to prepare to get one ticket every nine times you pass a photo radar camera!
Claire Corbett, "Road Traffic Offending and the Introduction of Speed Cameras in England: The First Self-Report Survey." Accident Analysis and Prevention, 27:3 (1995), pp. 345, 350:
"...it is also apparent that those drivers who report adopting the most excessive speeds in general are the most likely to report driving more slowly in the presence of cameras, but no differently or [even] faster in other areas."
"...the most regular users...were most likely to go fastest on that road, to slow down when passing a camera site, and to be best able to estimate the number of cameras."
Undesired Result: Tourists and occasional drivers are more likely to be caught by cameras.
Cheryl W. Lynn, Wayne S. Ferguson, and Nicholas J. Garber. "Feasibility of Photo-Radar for Traffic Speed Enforcement in Virginia." Transportation Research Record, 1375 (1992), p.16.
"Public opinion polls in Pasadena and Paradise Valley indicate that motorists favor photo-radar use in residential areas on local roadways, but virtually all of the ticketed drivers are nonlocal. ... those least affected by potential photo-radar use ... were the most positive concerning its use."