I for one am looking forward to driverless, on demand transportation. I would love to get rid of my car, insurance, taxes, maintenance etc.
Historically speaking, we tend to end up paying for those reduced costs in other ways. People used to complain about the cost of keeping horses healthy and fed and groomed and housed, but we ended up paying far more to upgrade our dirt roads to pavement and spent trillions pumping oil out of the ground, not even mentioning the environmental or health consequences of our transition to the automobile. Cars are not cheaper than horses. They are better and more expensive.
So I expect the same sort of thing could happen with transitioning to shared autonomous cars. Yes you'd lose your personal insurance and maintenance costs, but those same costs would get rolled into the cost of whatever sharing service replaces your personal car, plus whatever additional costs you need to pay for the superior service.
One thing to keep in mind as we envision this future is how are the roads going to be paid for. This funding has to come from somewhere. The government may start taxing rides (usage based), increase property, sales and/or income taxes, or find some other way to replace the funding lost from declining gas taxes. The pessimist in me says that will do all of these and then still say they need more money for roads.
Gas taxes are a rough proxy for road costs, but unfortunately they don't scale linearly with vehicle weight so in practice individual drivers are currently subsidizing freight transport. A more logical model would charge people by both distance traveled and weight transported over that distance, with the road maintenance portion scaled to the damage-causing weight of the vehicle. I think construction equipment should absolutely pay a higher per-mile charge to drive on residential streets than should Miatas. A few short weeks of regular dump truck usage can totally destroy a city street. Our current model shares these costs with everyone, which means some people who drive big trucks pay less than they should, some people who use the roads for bicycles pay less than they should, and average daily commuters pick up the difference.
Can you envision a world where AI-controlled autonomous vehicles deliver goods and people wherever they need to go in a big-data sharing network that actually tracks fuel consumption, distance covered, and weight delivered, while simultaneously offering a sliding price scale based on what each trip actually costs? Long haul truckers are probably going out of business in a hurry to be largely replaced with trains. People who want giant pickups to take their kids to school are going to pay for the privilege. Carpooling would be not only financially incentivized but automatically scheduled for you. And all you have to do is give up the privacy to drive a dead body out to the swamp at night without anyone knowing about it.