You might scoff at this, but Americans are largely law-abiding people. Unfortunately, there is a dramatic exception to that in the speed-limit laws. Why do American drivers so routinely ignore the speed limits?
I can only speculate, but I believe it goes back to the 55mph speed limit imposed by Congress in 1974. It was based on faulty assumptions on the amount of fuel that would be saved. Americans ignored the law on a wholesale basis. "Convoys" of commercial trucks conspired to evade it. Many people played traffic-cop roulette by just ignoring it.
The law was not repealed until 1995. Thus, a whole generation of drivers grew up knowing the speed limit was unrealistic. The problem is exacerbated by the fact that speed limits are often set by bureaucrats sitting in offices who have never driven on the highway in question. It's very annoying to drive five miles on a segment of road fit for 75 when there's a 55 mph speed limit on it.
For example, in Atlanta on the Interstate highways, there are huge signs, "SPEED LIMIT 55." Drive 55 on those roads and you will become a dangerous traffic hazard. Drive 70 and people still pass you on the right and left. When the vast majority of drivers exceed a posted speed limit, it's the limit that's wrong.
In the end, all this is very bad because it nurtures the attitude that the law does not matter. This affects other behavior; texting and driving is a good example. In fact, it helps breed a negative attitude toward laws in general. To be respected, a law must be respectable.
Speed limits should be set realistically and enforced.
Justin Bertrand Galen Skywatcher