I think another leap can be achieved with communication between vehicles. Once there are many more self-driving cars on the road, they can feed info to each other as needed. A car experiencing black ice can pass that info to the cars around it. Cars approaching an intersection can adjust their speed so that they all pass through without stopping, etc. But, because there are several manufacturers, this will be hampered without an open standard, and it doesn't solve the randomness of the world that will still be experienced.