edit: I don't mean to dismiss the student's accomplishments, but wanted to bring some perspective
And for the entire fleet of autonomous cars, the system does not need to be safe. It just needs to be better than humans driving. Realistically to gain acceptance they would need to be an order of magnitude better, which translates to roughly 1 fatal accident per year per 10^5 self driving cars. The current numbers for the US are 36000 fatalities and 250M cars.
I really hope this is true. I really want self-driving cars everywhere, now. Road Traffic accidents kill very many people and this is an example of Google using money and smarts to do good.
But looking at the way people deal with risk makes me wary.
People drive cars all the time even though driving is a bit risky. People don't really understand how good or bad their own driving is. There's a bunch of cognitive biases and rationalisations.
I hope people who are experts in communications are ready to dispel the FUD backlash against self driving cars.
One of the problems is insurance. Right now, everyone needs to have insurance to drive. If I accidentally hit a pedestrian or rear-end another driver they can claim on my insurance.
Let's say that a software bug results in someone getting hit and injured by a self-driving car. Who's liable? I am not sure that this is FUD, so much as a genuine question. It is because driving is risky that drivers must have insurance. Presumably most people would want self-driving cars to be insured if there was a chance of failure (even planes, one of the safest forms of transport, get insured against crashing).
We could very well have a situation where cars self drive, but drivers are still expected to pay attention to the road and 'drive' to avoid liability.
I suspect there's going to be a lot of lobbying on both sides before mass deployment of self driving cars.
On the other hand, I think that the politics of self driving cars could get rather interesting, especially if widespread adoption is fast, say 5 years until a self driving car is no longer extraordinary and 10 years until one just assumes that a new car is self driving. Then I think we get a initial phase, were they are seen as modern. After this, when every single accident gets widely reported, I think it is possible that the public completely splits, on one hand the traditionalists, who maintain that only a human should drive. And on the other hand the people who say that self driving cars are safer than humans. And the laws will shift according to the relative strength of the two groups. ( With probably some rather ridiculous political compromises in between, perhaps you are allowed to read a newspaper, but not to drink coffee. )
The same person who is liable if your current car has a fault tomorrow that causes you to crash, presumably.
Or Google might take him to work for them :)
It's that last 2 percent that's the most challenging.
To mitigate the issues in complex systems like planes and so on, the systems are built with multiple redundancies in place. That way even if something fails, the system remains stable and operative. So you don't need to have a "per trillionth" (and you are using the wrong word) quality system in order to deliver a very robust system.