- Why does everyone drive 10-15 miles above the speed limit?
Because speed limits are designed for the largest, clunkiest vehicles on the road (semi trucks, specifically). If they can't handle the road at a certain speed, then the speed limit is dropped to a level that can be comfortably driven by them.
This means that the average car can drive comfortably 10-15 MPH faster than the posted limit. And a lot of drivers feel that desire to drive faster.
Also, I don't know if it's still a thing, but in my childhood (roughly the '90s), cops wouldn't pull you over for speeding unless you were going at least 10 MPH over the limit. The reason being, the speed detector equipment they used had about a 10 MPH margin of error. If they pulled you over for driving 7 MPH over the limit, you could argue in court that their equipment was faulty and you were being unfairly assessed. You could sew seeds of doubt and get the traffic ticket stricken down. So cops just didn't bother unless you could be positively identified, without a doubt, as speeding.
I don't know if the accuracy of their equipment has improved since then, but the mentality back in the day was that you had some leeway with how fast you were driving, leading to people driving faster than the limit in most places.
- Why don't we raise the speed limit if that's how fast everyone wants to go?
Because it risks all vehicles - including semis, RVs, delivery trucks, etc. - driving too fast for their large, heavy, awkward bodies to handle. Then they become a hazard on the road. You ever see a semi tip over because it took a corner too fast? If you're in a car next to it, you're pretty much toast.
It's like queueing in line. Sure, it would be faster to crowd toward the front, but you're pushing people out of the way; people who may have been there first and deserve a turn before you. And depending on how aggressively they're crowded out, it may become hazardous for some people.
In the interest of fairness, everyone queues and respects the line, so the system stays safe and orderly. Same with speed limits. Everyone is expected to stick to the limit so ALL traffic on roads are safe and orderly. But sometimes, people are people and will do whatever they want, even at the expense of their fellow human beings.
- Why is traffic enforcement given to very expensive and ineffective police instead of cheaper and more automated traffic cameras?
This is a discussion that's been going on for decades now. I know traffic cams are set up in some European countries and work pretty well, but here in America, historically, we've had a thing against being recorded publicly. Traffic cams haven't taken off here because the idea of a small camera recording data about our cars without our knowledge freaks us out.
Heck, we had to create entrapment laws to prevent cops from hiding while checking speed limits. If you watch old cop movies, they'll sit behind billboards and catch speeders who fly by. That's illegal in the US nowadays; cops have to be out in the open and visible if they're going to watch traffic for speeding. It gives a fair chance for drivers to check their speed and adjust before the cop records them speeding and gives them a ticket.
But most people will miss a camera in the wild. There's no chance to argue a speeding incident in the moment. You get a ticket in the mail a few days later, then need to think back to that day and try to remember where you were and what speed you were going. You can fight it in court, but good luck having any evidence to counter a camera, unless you were recording the interior of your vehicle that day.
With all that said, Flock cameras sprouted practically overnight here in the US and have set off distopian levels of surveillance paranoia. Especially since their setup was so fast that no laws or safety measures have been respected in their usage and the system is already being abused to watch and track people in unprofessional capacities. We kind of skipped the whole traffic cam issue and went straight to 1984 levels of public surveillance. So we'll see how that plays out over the next few years.
- Why do we refuse to ever use ANY traffic calming measures?
What kind of traffic calming measures do you have in mind? You mentioned the flashing speed limit signs, but that's not going to stop some people. Speeders are gonna speed. It's just human nature. The system we have is ineffective in a grand scale, but it works as a mental deterrent for most people. The fear of being pulled over by a cop for speeding keeps a lot of drivers in line.
I once drove in the small African country of Djibouti, where the government had to post signs every mile to remind drivers which side of the road they should be driving on. Driving education was available, but most people just hopped in a car and took off; no license or training. There were accidents every couple miles. Trucks flipped over and abandoned on almost every sharp corner. Potholes so big you might lose a car in them.
The system in America isn't perfect, but it's a whole lot better than it could be. You're never going to stop people from speeding, even if we did set up cameras everywhere.
My final thought on the whole matter is that speeding tickets should be based on a percentage of annual income. Say, 5% or so. Because a flat rate for speeding is just a punishment for poor people. Rich folks can afford to pay a fine with what amounts to pocket change for them, so there's no incentive for them to correct the behavior. Correct me if I'm wrong, but I believe it was Steve Jobs who refused to get a driver's license or plates for his car or something? Every time he got pulled over, he just paid the fine and continued on with what he was doing. Meanwhile, someone living paycheck to paycheck is going to have their life ruined by a fine. If you ask me, making fines a flat percentage rate is the first step to curbing bad driving practices. Punish people fairly across the board.