I predict that there will never be self driving cars in mass. I just don't think any computer can be smart enough to adapt to wildly changing road conditions, and by the time such technology is worked out, self driving cars will be illegal due to liability concerns and ghastly crashes that are widely covered by the news. Stories of police officers and young children run over by self driving cars with helpless passengers will shock the public in banning them.

Plus cheap oil is running out and there won't be enough coal to power the plants to run all of the cars and by then many places will be dealing with the death and destruction brought on climate change.