If something goes wrong, as we've seen with Tesla, the car tends to barrel full-speed into very solid obstacles.

Because, duh, something went wrong.

Human errors tend to be misjudging something and then getting into a situation that, due to physics, they can't quite get out of. So you can't quite stop the car in time and you hit the car in front of you at 15mph.

Car errors are going to be things like "I thought the tractor trailer was a billboard or a bird so I hit it at 60mph with no braking". Or "I lost all sensor data and got stuck in a loop so I drove off the bridge". It's a fundamentally different sort of error.

People also fall asleep at the wheel, with cruse control there now driving randomly.

I watched someone driving on a nice sunny day on a low traffic interstate suddenly make a sharp right turn crossing our lane to fly off the highway and start rolling. I have no idea why this happened, but everyone in the car survived so it's not even part of the traffic fatality statistics.

Really? So easy to think of scenarios where there _is_ no safe answer.

For example, what if it's dense fast traffic (say, one car space between each car, 50mph) in random black ice conditions and sensors suddenly begin failing so the software no longer trusts is inputs? Based on recent good inputs, accelerating, swerving, or breaking are all dangerous, and based on the loss of "vision" continuing at current speed is dangerous. The safest thing to do might be to begin honking, flashing hazards, and slowing down very slowly, but could still be way riskier than just handing control to a human driver who (in this scenario) can still see.

I can think of tons of similar situations. I have a feeling a lot of folks who think it'll be so easy are people who have mainly experience driving in easy areas and conditions.

EDIT: I could have easily made the scenario way worse: the road is curvy, or random lanes are closing and reopening due to construction. Loss of visibility then means continuing straight has a high chance of causing a serious wreck quickly rather than maybe eventually

In that situation I'd rather trust my life to that computer software than to a human driver (including myself) who simply couldn't be trusted to act safely if their vision was suddenly impaired.

Still, no driverless car should ever let itself be in dense fast traffic to begin with. Only a human driver would ever be dumb enough to do something so stupid and dangerous.

I would expect all high speed roads to be continuously validated by the car network, mapped in detail and kept up to date by the sensors of each car as it drives it. Your car should be streaming a model of the upcoming road from the cloud and be able to fall back onto it in the event of sensor failure.

Handing over control to a human driver only works when one is actually in the car. And paying attention. And competent.

> what if it's dense fast traffic (say, one car space between each car, 50mph) in random black ice conditions

I would assume that a self-driving car would allow more than 1 space between cars when going 50 mph, and probably wouldn't be going 50 mph when there's black ice around.

Hell, most humans wouldn't be.

> Really? So easy to think of scenarios where there _is_ no safe answer.

Then the human is no better or worse, no?

One of the improvements is that an autonomous car will avoid getting into a situation it can't dig itself out of. And, at times, it will detect those situations long before a human will.

My favorite counterexample for people like you is driving in Southern California in the rain. An autonomous car NOW is probably better than 25-30% of the drivers on the road in that situation.

You assume that the program will recognize the edge cases. But will it recognize the edge cases of recognizing the edge cases?

Most of my driving (as in 90% by mileage) is on highways, and most of that is 70-mph rural highways. The first edge case I'd think of, totally not a weird edge case at all, is sudden 0-visibility fog banks at 70mph. If you think it is a good idea to slam on the brakes in such conditions, someone is likely to lose a life.

No driverless car should be wholly reliant on visible light sensors. I imagine that an accurate map of the road ahead and front-facing radar would be all that's needed to respond to the situation as safely as any human driver could.