This seems like a good time to question if we really should have cars at all. Autonomous cars might be better in some ways but they are still tons of metal flying at high rates of speed. Accidents will happen and people and other animals will die on a regular basis. Cars also require tons of infrastructure that walking and biking don't. You also have the environmental destruction of GHG emissions and from the mining of rare metals needed for batteries, you have roads and parking lots destroying habitat and using up valuable space, air pollution and smog from tailpipes or energy generation, noise pollution, and more harmful effects. Autonomous cars might mitigate some of those things but most of it will still be there (or we'll just use cars even more and so we'll have just as many deaths total along with the rest of it?). What about doing research and testing a world without any cars? It will probably be a better one.