I kind of want to weigh in on this. I think there should be cameras on traffic light arches. In our little corner of the universe I've seen, over the years, a growing trend of disregard for law. In the case of driving, speed limits are merely suggestion, red lights are merely suggestions. The purpose of speed limits is public safety, not punitiveness.
Statistically, the purpose of speed limits is revenue, not safety. I'm not saying that speed limits aren't useful, but I guarantee that having a 25 MPH speed limit on very nearly every single road (including major five-lane city-street highways) through Santa Cruz is not for safety. Despite being in ostensibly a zero tolerance state, the cops gave up bothering to pull people over for less than about fifteen over... a couple of decades ago.
CA-9 south of Saratoga has a 45 MPH speed limit, but if you try, you will die. On the flip side, there's one stretch of access road along the freeway in Sunnyvale that has a 25 MPH speed limit for something like two blocks, for no obvious reason. Everybody drives 45.
The interstates through Nashville are marked 55. If you drive slower than 70, you will get run over. If 90% of cars are going more than 15 MPH over the limit and you aren't seeing a crazy number of crashes, your speed limit is pretty much guaranteed to be
at least 10–15 MPH too low.
So no, speed limits are mostly a joke at this point. They stopped being set sensibly and started being set ridiculously low for revenue generation a long time ago. I wish it were not so, because that practice makes the few spots where the speed limits actually
are there for safety a lot more dangerous, because people ignore them, and then they flip their cars.
When I was in my 20's I scoffed at speed limits I didn't agree with, "I could navigate this section of road at twice this speed". It's not just for your safety, it's for everyone else's. Alert! - huge jump ahead. We're either a country of laws or it's every man for himself, aka, anarchy. As a society starts to break down, it does so from the edges first.
Quite the opposite. Most people still pay attention to sensible laws. The more ridiculous the law, the more people ignore it. If you put a 5 MPH sign on a freeway, people won't even slow down. If you put a 65 MPH sign in a residential neighborhood, people also won't speed up. Most people have a decent intuitive sense about what is safe. That's why IMO, for the most part, speed limits
shouldn't even exist except in places where the reason for those speed limits is not immediately obvious. Nearly everyone will still drive a reasonable speed for the road, and the speed limit signs that do exist will immediately jump out as critically important.
Speed limits are rather like California's Prop 65. It started out as a way of warning people about truly dangerous substances that can cause cancer and reproductive harm. And over time, the desire to protect people from smaller and smaller levels of harm, coupled with the existence of fines for not warning people, but no fines for warning people unnecessarily, has weakened the impact of those signs to the point that everyone ignores them entirely.
The problem is, local governments, in an attempt to raise revenue, have been crying wolf for way too long. After a while, when the real wolf appears, everyone gets eaten.