They can be a pain, the wife and I've gotten their tickets & bitched, but you guys are like most people in adding a lot of hype, too. There are some around that I just can not see the use of, and they are Orwellian. I a not a big fan of these things, but I'm in Maryland with one less than a mile from my house and thought I'd throw out some facts.
The one near my house is in front of an elementary school (Woodfield on Rt 124) and it's a main road from the next county north, going toward DC or suburban shopping. We had some hellacious accidents from the never-ending flow of 55-65 mph traffic T-boning people pulling out of drives and side streets. The medevac helicopter knew our school's ball field too well, including for some neighbor's kids. Say what you want about Orwell, the thing has worked. People still come to it quick, but not as quick as before, are on the 30 mph limit through the zone, and then speed up to the mid 40s.
The speed cameras have not had the rear-end collision side effect that the red-light cameras have, probably because people anticipate the speed cameras and slow, they don't slam the brakes.
They aren't hidden and actually easy to spot. First, there's generally a white sign telling that one is ahead. The box is generally easy to spot and for the people too pre-occupied to miss that or the sign, there are lines painted on the road. See lines = slow down. The response almost is like Pavlovs dogs. They use the lines to verify your speed between 2 photos, so it's not really just you versus the single source of speed measurement. btw - radar detectors pick them out long before they get you, and same for most (not all) of the red light cameras. They still nail people left and right, so it hits me as an indication about how dense/pre-occupied those drivers must be.
There is an appeals process shown on the back of the ticket.
They can't assign points to your license because there's no proof about who was driving. The ticket goes to the registered owner. If the ticket doesn't get paid, the fines add quickly since they are on a per-day-late basis and you won't get to renew your tags till you pay up.
I don't know of any that are set 2 mph over the limit, at least in DC or MD. It's pretty common to hit them at about 8 over, knowing that they are set at 10-11 over the limit.
Here is a more thorough article on them:
https://www.washingtonpost.com/wp-dyn/conte...9040201721.html
As for the money-making aspect, note in the article that they are really only big money makers at first. People learn pretty fast where they are and second year revenues are a fraction of those from the first year. Plus, Maryland's new law says that the counties or towns with the cameras can only make up to a certain cap in income from the things to discourage the cameras from actually becoming revenue devices.
They've gotten my wife while on the cell phone (visible in the photo). They've gotten me when pre-occupied or thinking I'm 8 over when they've had me at 11 over. The two things that are the biggest risk to me are the TEMPORARY speed cameras that are mounted in Ford Windstar vans and the fact that some red light cameras are now also being converted to dual function, to also be speed cameras. The Windstars are again pretty easy to spot and they put the signs out, but they're just not same place-different day.
And if you want to see the cameras in full force, rent a car or bike in some of the European countries. England and the Netherlands seem to have them every other block.
If you don't want to see them at all, don't live or drive where there is enough traffic for the county to justify putting one. Because like 'em or not and ***** all you want, the camel's nose came under the tent and they are now a fact of life that's here to stay.
Bob
I wouldn't apply what you know in NH to CA...because even I know WA is different than CA and NH. 
