When people have already bought a car and paid a flat insurance rate, the marginal cost of another car trip is very low. Thus, people who own cars don't really make a choice very frequently. Their choice has already been pretty much made once at the outset.
Because carsharing services will almost undoubtedly be the first deployments, self-driving cars cannot come quickly enough for me. I think the net effect is that they will drive (har har) more people to adopt carsharing services. Self-driving cars will solve one of the inconveniences of something like Car2go, namely the need to walk some indeterminate distance to a car.
If they can get more people into an a la carte transportation usage model, I anticipate public transit and non-motorized transportation options will benefit greatly. Since trip costs will only be marginal, the choice to do something other than drive will come up routinely.
As self-driving carsharing fleets replace the >90% idle private vehicles of today, we'll need less land for parking. My hope is that on-street land can be given over to wider sidewalks, better quality bicycling infrastructure, and dedicated transit right-of-way, which will make those modes even more competitive.
In part because I've been personally touched by the mass slaughter on our roadways, I left a career in information security to retrain / work as an urban planner focussing on transportation. Oddly, the nearishness of self-driving vehicles is pushing me back in the direction of my former career. I'm bullish enough on the potential of self-driving vehicles to remake the economics and safety of transportation that I'm now pursuing a PhD researching privacy / security aspects of the "smart city"--including on-demand mobility services. If we can get all this suitably right, I think it will be transformative for society.
I got so annoyed when family members would say "just rent a car and come down to visit us". It's not cheap, it's not easy, and it's not fun.
Renting a car in Stamford, CT is cheap, ~$70 a day.
Zipcar now have differential pricing (i.e. more expensive on weekends), so a 24 hour rent Mon - Fri is under $100.
Expensive, you may say. But... I pay only $70 per year for a full insurance waiver, all fuel is included, and there are no maintenance costs or other hidden costs.
Last Zipcar I got I used almost a full fuel-tank worth in a 24 hour period. Subtracting fuel from the price put the days rental at about $40. And there's a pod across the street from my apartment (and about a zillion other pods nearby, here in Berkeley CA).
I have friends with a 2-kid family in Manhattan and no car. They use Alamo, and claim it's cheap and easy.
Renting is expensive. Owning a car is also expensive, with more 'hidden' costs that people frequently ignore.
I live in the SF Bay Area. I work in downtown San Francisco. When I lived in SF proper, it would usually be faster to walk somewhere than drive, because of traffic. Then factor in finding parking. Then factor in paying for parking (upwards of $10/hr anywhere important). Add the stress of driving in dense areas, moronic pedestrian tourists who wander into the middle of the the streets, cyclists who seem to have a death wish, and other drivers who act like it's an aggression competition
Now I live across the bay (I got gentrified out of SF), and it's even worse. The freeway nearest me is bumper-to-bumper stop and go across 5 lanes of traffic, for 3 hours in the morning and for 3 hours in the evening. Everyone is just as aggressive, but the speeds have quintupled.
Bignaj mentions freedom. Shortly after buying my car, I went up to Portland for a conference. I thought, FUCK YEAH ROAD TRIP. Well, for one, turns out 11 hours of driving in one day is hard. I looked at the radio at the wrong moment and almost killed myself. I burned about $250 worth of gas round trip. And once I got to Portland, parking was $30 a night. After the trip was over, when I came home, I priced out airplane tickets. A round trip for both my girlfriend and myself, was cheaper than the cost of gas + parking in Portland. It would have saved us the better part of a day's worth of time (at Bay Area tech salaries, $400), and it would have given me a 100% reduction in near-death experiences. Maybe it's because I'm Canadian, and used to Air Canada prices, but airline travel is so cheap in this country that, for the vast majority of places people want to go, flying there is cheaper and easier than driving. I don't see how car = freedom in that regard.
I own a car. I wish I didn't, but I already have it. It's paid in full, I have a flawless driving record so insurance isn't that bad. I like going on day trips hiking. I've run the numbers, renting a car every day I want to hike would be cheaper than buying the car, but the car is already bought and depreciated at this point so too late on that. I would've traded my car for a smart car or scooter years ago if it wasn't for that. And I'd be doing without that if I could afford to live in a walkable place here.
Cars are horrible, and most utilitarian arguments for them are terrible.
And P.S.: That horrifies me too. Every 3 months, one 9/11 worth of americans die in motor vehicle accidents. We haven't declared a war on driving yet