If I get the replacement parts for my vacuum cleaner for tomorrow, I won't get in a car or any transportation mechanism to get it to some store. As a side effect, your traffic accident number is down (less individual people driving) and the system efficiency is also up (efficient vehicles moving the goods).[]
What amazon does goes toward the goal you state. It does it in a small way, but it's here today, you can use it now, and it should continue doing it better and better everyday.
Google's self driving car might reach your goal to some point in some distant future. If infrastructure gets a lot better. And legislation problem get solve. And Google is still around by then. Is it so much better ?
[] BTW, You'll still have drunk people, but this problem might as well be solved by other means than self-driving cars.
Self-driving cars could be a part of that. But small in the bigger picture.