In the interest of full disclosure: Yes, I speed, in some circumstances. I do NOT speed in residential areas or shopping districts, and only very rarely in places where lots of people are working.
Speed limits are arbitrary numbers set up to ensure that there are some minimum number of violators, so as to keep revenues up.
Yes, at any given speed, an increase of n mph increases the probability of an accident by x percent, and the seriousness of the accident by y percent. The relation is fundamentally a square, because of the momentum involved. We who drive calculate that probability [very optimistically, I'm afraid] and balance it against the "goodness" of getting there more quickly. If you're not willing to make that tradeoff, then any nonzero speed is "too dangerous".
Last week I traveled over 1400 miles. At 50 mph that would have taken 28 hours; at 70 it took 20 -- clear profit of eight hours, since I didn't hit anything. Please note that that eight hours profit was not accrued just to me -- my companion received the same benefit, and (if it's true that I'm providing a useful service to the economy) so did the economy as a whole, in that that eight hours was available to the world in general as work time from me.
Sadly enough, there are a lot of people who also speed in non-highway conditions: neighborhoods, parking lots, dense business areas. The clearest proof that the assertion I opened with is there, too. Find a cop in a neighborhood, especially a poor one with kids playing in the street. Find a cop patrolling the tiltups. It's a useful exercise to have an accident in a residential neighborhood. If you want a cop there in less than two hours, about the only way is to get a neighbor to report that somebody has a gun.
If "speed limits" equaled "safety" then the police would concentrate their efforts on construction zones, residential neighborhoods, and busy shopping areas. Instead, in the United States at least, the place you'll find them is on nice, long, straight stretches, the flatter and less traveled the better, with their radars out. Stretches where the posted speed limit is at least ten MPH below the rational one, so as to maximize their take. And if the traffic density rises above a certain point they disappear. At eight AM you can travel as fast as you like on Airport Freeway in Fort Worth -- there won't be a cop within two blocks, because it's dangerous out there; the result is that the "flow" occurs at around seventy. But at ten PM, keep it below sixty -- they'll ticket you for five over, because there's nobody around for them to dodge. There's also the small town I have to travel through occasionally. The town is newly incorporated, and wants to make its mark on the world, so they cut the limit on a country road by ten MPH and bought a new police car. People have noticed, I assure you.
And the worst part is -- scofflawing on those grounds gets overgeneralized. The State of Virginia has some of the stupidest speed limits I've seen -- way too fast in residential neighborhoods and shopping districts, way too slow on the Interstate -- and the police are all concentrated on the Interstate. It's real easy for a driver to look at the artificially low, revenue-generating limit on the Interstate and say, "Well, that's full of shit. How much of the rest [of the regulations] is full of shit too?"
Funny thing, too. I'm a middle-aged white male, and when I'm speeding I'm usually in a van that looks businesslike. I've been stopped, but not very often -- and it's common for me to see drivers being stopped who were traveling at about my speed, or less. Remarkable that they all tend to be (1) young, (2) black or hispanic, and (3) driving nice cars, eh?
Another funny thing. Here in Texas, a few years ago, most of the speed traps just disappeared. Even Estelline! I couldn't figure it out. Turns out they'd changed the law about speeding fines -- most of the money now goes to the State, who dole it out according to the population of the town or county. Truly remarkable how "unsafe" speeds suddenly became "safe" when there wasn't as much profit in it.
Many States have differential speed limits for heavy vehicles. Cars 65 or 70, trucks 50 or 55. I know of no state that enforces those differential limits -- we certainly don't here. The reason for that is left as an exercise for the student, but it's one of the really big places where the "that's full of shit" reaction occurs.
So no, speeding itself isn't malum in se. In most places it's barely malum prohibitorum -- mostly it's finding ways to pay of the JP's new Cadillac. And if you don't drive regularly, you'll probably wind up being real impressed by the speeches in council about "improving the safety on the roads" by setting up roadblocks. It's a nice way to cut your tax burden, isn't it?