Here was goatinaboat's initial concern: > One bad software update kills... everyone. That's a fair concern. If you push a software update out to a hundred mil

Here was goatinaboat's initial concern: > One bad software update kills... everyone. That's a fair concern. If you push a software update out to a hundred million cars at the same time which causes some of them to crash into oncoming traffic at high speed, you could have a large number of fatalities by the time you identify that there is a problem with the update. But phased deployments do mitigate that concern, because it provides time to notice the problem before the bad update is more widely deployed. That doesn't imply "treating humans like beta testers" because systemic risk is a real concern even when you have thorough internal testing. Even a thousand test vehicles will not encounter the full set of conditions that hundreds of millions will. You would expect to see a flaw that occurs for one vehicle out of 2000 occur 0 times on a fleet of 1000 test vehicles but 50,000 times on an installed base of a hundred million. Having a total of 50,000 fatal traffic collisions in one day is totally unacceptable, but having 10 on a bad day would mark a significant improvement from the status quo.