I think driverless cars are going to travel more slowly near pedestrians, though they will also take advantage of knowing exactly where they can swerve in a pinch and that will reduce their constraints somewhat. Humans take stupid chances because they think they're better drivers than they really are; deep pockets will be responsible in the case of the driverless cars, and they'll be accordingly more careful.

You also have to consider the possibility that some pedestrians may be quite aggressive; certainly, if a driverless car tries to push its luck at a crosswalk, sooner or later it's going to get a shopping cart shoved into its grill, or get the studded tires of an (ahem) icebike rammed into its side. I know dads of kids at the local elementary school who would throw snowballs at the windshields of cars that didn't stop at the school crosswalk (no crossing guard, the police said it was "too dangerous").

The car does have brakes, and "at speed" is not that large if you're a conscientious driver in a place that's already got pedestrians in it. If people are tailgating you, then you driver slower yet, so as to reduce the stopping distance that they'll need or increase your ability to stop both cars quickly. And yes, I know that you can get rear-ended stopping for pedestrians, it has happened to me, and I saw it happen to someone once who stopped for me (at a crosswalk, thank you very much). The law (at least in Massachusetts) is pretty plain; you have an obligation to not hit the pedestrian. You do not have any obligation to yield to the non-emergency vehicle behind you. Arguably, honking your horn to indicate "I intend to break the law" is also a safety issue.

The issue is also one of self-training -- if you train yourself to always hit the brakes instead of preferring the horn, then when you come across the pedestrian who doesn't hear, is too young, or mentally not all there, you'll still stop fast.

I wait to see how long they'll stay asleep.

Believe it or not, in more than one state the vehicle code says that the horn is only to be used when reasonably necessary to avoid an accident. Your recommended use of the horn is illegal in many places, though the law is practically never enforced.

I think your homemade statistics are correct. A few years ago I came to a similar conclusion, and decided that I would not use my horn if it were possible to solve the problem with my brakes instead.

A conscientious driver would use the brakes instead; they work better. Honking a horn depends on the person who needs to hear it, hearing it, figuring out that it applies to them, figuring out the appropriate response, and responding. They could be deaf. They could be distracted. They could be mentally disabled in some way (we have friends with an autistic son, he went walkabout one fine morning, quite the panic, till he turned up two miles away). Or, you can just step on the brake, stop the car, and wait for the problem to clear more sedately.

And yeah, you might be delayed a few seconds. I think that's less important than not hurting people.

"Discrete mathematics" -- I don't think that word means what you think it means.
(I know a whole lot more about discrete mathematics than I do about statistics or climatology.
Look it up on wikipedia, see if you see very much at all about sampling theory or statistics.
Yes, they DO mention discrete probability, but it is a tiny corner of the whole.)

No, you're a fucking idiot. 1000 samples is plenty for many purposes, if they are good and random.

Don't know if you've ever compared the three amounts of energy, (1) solar energy incident on the earth in a year, (2) heat of fusion of the Greenland and Antarctic ice caps (i.e., energy to melt them, assuming they are at 0C and frozen) and (3) the amount of energy required to heat the oceans by 1 degree C. The ratios are roughly 1 : 1.8 : 0.9. (My arithmetic: http://dr2chase.wordpress.com/2012/02/04/numbers-that-were-larger-than-i-had-imagined/ )

For me, this was simultaneously stupefying, scary, and annoying. Scary because the thermal mass of the ocean is incomprehensibly large, which means that burps and blips in the South Pacific can overwhelm any minor atmospheric effects, and annoying because in any discussion with internet "experts", no matter how correct it might be to blame the ocean, neener-neener-Al-Gore-said-it-would-be-hot-by-now.

"These types of devices allow insurance companies the ability to prejudge you, without relying on your driving record."

I take it you've never been a male under 25 years old with a driver's license? Insurance companies do this stuff all the time.

For either sense of the word "blind", if there's a pedestrian and it's a crosswalk, the law says you're supposed to stop for them. They are not supposed to stop for you; they have right of way. If visibility is not so good, that is presumably because the highway department assumed that you, an allegedly safe driver, would reduce your speed correspondingly so that you could always see the pedestrian that you are legally required to stop for. If you are ever honking at a pedestrian in a crosswalk, or a blind pedestrian crossing a street anywhere, either your brakes have failed and you are warning them of this unusual hazard, or else you are doing it wrong.

If someone's approaching a stop sign at a high rate and it doesn't look like they are going to stop, the safe thing to do is brake ahead of time. For honking at them to work properly, many things have to happen in a timely fashion -- they have to hear you (dead people can be licensed), they have to figure out you are honking at them, they have to figure out *why* you are honking at them (presumably, if they saw the stop sign, they would stop for it, right?), and they have to react. Ideally, if the reason they were not stopping was that their brakes had failed, they would already be honking their horn.

The overwhelming use I observe for horn use is "the light is green and you're not moving". That is not a safety issue -- cars not moving is in fact quite safe, albeit frustrating.

I don't suppose that my car's computer could have a little chat with your car's computer, maybe they could coordinate?
Seems like one of the very first things that smart-ish cars should get right is not running into stuff that is right in front of them.

And we have that problem now, with ABS. A couple of years ago, renting a car, junk flew off a truck in front of us and everyone stopped fast. The guy behind me did not have ABS. Oops. Royal pain with all the paperwork, but in the end, yes, it was their problem.

I don't think the pedestrian does know that you will stop in time, but a certain number of pedestrians aren't paying attention and this could help them. Defense in depth, after all. The few crashes that I've watched happen (and one I heard recounted in which a cousin was killed) all involved multiple coincident screwups. Not one was caused by a single point of failure. Cars currently kill thousands of pedestrians each year; there's plenty of room for improvement.

And we do manage to (eventually) design safety devices that result in a solid net reduction in harm, so I imagine we could get this one working pretty well, too. Airbags we (finally) got right. Seatbelts are low-tech and effective. ABS braking is pretty startling compared to old-style (I've never owned a car that had it, but I always check out the new features in rental cars).

You don't "protect" the pedestrian by telling the bad driver to activate his brakes. Instead, automatically activate the brakes, take the bad driver out of the loop.

This is similar to my gripe about people who think that a horn is a useful safety device -- as if the guy who you are beeping at is going to listen the horn, figure out that it applies to him, and figure out what he is doing wrong, fast enough to make a difference. Better to simply assume that he's an idiot, and work around him.

I am not at all sure I follow your logic. If not for 9/11, we'd have none of this security theater nonsense. People born post 9/11 are affected by this even if they were not around on 9/11 (and relatively few people were directly affected -- closest I get is multiple friends-of-friends, and I live in a Boston suburb), and it may cause them to change their travel preferences. Most people experienced it only on television -- is there a difference between seeing it live, versus on video? It seems like you are make a fine distinction that is not necessarily justified.