Reading here and on social media about the inevitability of deaths from driverless cars so we can be on our merry way to less deaths from cars is grotesque. So I'm going to rant a bit.
I agree with others who have stated that nothing less than no deaths is acceptable.
Here's my take on requirements for this thing.
1. It's my unsubstantiated guess that these cars are programmed to be in a state of "go" unless there is a good reason to slow down or stop. I would mandate the opposite - their normal condition must be "stop" unless there is a good reason to go.
2. If the software is in a situation where it cannot accurately determine what's going on, it must immediately signal the driver and begin to slow to a stop or pull over and stop until the driver takes over. Continuing on with the "thought" that it will figure out what's going on is dangerous.
3. Companies developing self-driving cars must, for a minimum of two years, equip electric golf carts with the same software and detection equipment and let them continually drive around their offices (except when recharging). If you need a number, let's say 5 golf carts per floor. Incident reports must be maintained. After a period where there has been two years of no accidents, the company will be allowed to place their software and detection equipment on a car, and let the car drive around their property (including parking lots). After a period where there has been one year of no accidents, the company will be allowed to place one of these cars on a public road. (And so on.)
4. Company executives will be personally liable for accidents and deaths from their driverless cars.