If you have a better, safer alternative for us to develop this much needed tech, please share.
Closed environments and simulations. Simulations are better in particular because you can create test situations trivially, so you can test on e.g. a thousand variations of the same onramp. You can't really build the vision models in simulation, but that's OK, because you can build them by logging data from cars where the computer isn't controlling anything and therefore isn't endangering anyone.
This isn't new, though, this is obvious. You just want to move fast and break things.