The car sharing won't cover everyone's needs and some people will stick to keeping their own car. I'd imagine people living in urban areas are more likely to use a car sharing service since it's uneconomical to own a car in most cities. I'd imagine the suburbs will be a mix of sharing and ownership. I can imagine a family having a car they keep for weekends or whenever the parents and kids need to go somewhere but they still use a car sharing service during the weekdays when mom takes the family car to work and dad need to get to work too.

I think you're exactly right. Once cars can drive themselves to destinations, it becomes so much easier to get by with one dedicated family car, supplemented with car sharing services.

For example: Mom takes service to work, possibly carpooling. Dad takes uses family car to drop off kids and goes to work. Car drives itself to mom's work for her to use to pick up kids and commute home. Dad takes service home. Or whatever. The point is kids can always be in the car with the extra diapers, with safety features parents want, etc.

The other part of this that people ignore is that a car sharing service could open up a lot of flexibility. For example, maybe our dedicated family car is just a sedan, but on this particular weekend with the grandparents in town, we can use the car sharing service to get a minivan and have everyone ride together. Or I want to pick up a piece of furniture and request a truck from the service. Or it's my anniversary, and I can request a luxury sedan to drive us to the restaurant for a touch of opulence. I'm sure there are many other examples people can think of.

Like you say, car sharing won't cover everyone's need, especially at first, but eventually, the big players in the space will have enough sophistication to cover many cases, especially for a second car.

I think car sharing even works in those cases. It's all a logistical problem. Not that there won't be some people who own cars. There just aren't that many problems that are hard to solve with car shares to outweigh the huge benefits.

car sharing works less well for getting to work because everyone else is trying to get to work then. You may as well own your own car for getting to work because you pay for all the costs anyway. All car sharing buys you is fixed maintenance costs on your car.

Car sharing starts to make sense when you want the car outside of rush hour. Want to go to the store for an hour at 2:30, no problem there are plenty of cars free. Want to get to work every day - you are paying peak rates for a car that will probably be used exactly twice that day, once to get you to work and once to get you home.

"Rush hour" is actually a pretty long distribution of time compared to the average length of a person's commute. I imagine just considering commuting, you could likely get close to half the amount of cars required with car-sharing, since you may get in at 7:30 and I may get in at 9:00. And you could provide good price incentives to convince people to mix up their commute times a bit. I already know people who push their times significantly to avoid traffic just due to the stress aspect.

This seems as good a place as any to add the familiar lament: Why does no one build new commuter rail in this country?

(This assumes that you're also from the US, for rhetorical convenience.)

I think it comes down to cost. Its only effective in very dense areas. For example, right now I'm on an established commuter rail line going from downtown to a suburb. I'm paying $12 round trip to travel 60 miles total. It's just barely cheaper than driving (not including parking expenses).

At this point in time, I think it's wise to avoid laying costly new tracks with the dawn of driverless cars on the horizon.

I think there are physical reasons why driverless cars will never be as good as trains: they're rubber-on-asphalt instead of steel-on-steel, and you need a lot more engines, space, and transportation of dead weight per unit of people moved -- and they'll probably still need parking, too. As near as I can tell, driverless cars are horseless-carriage thinking... but trains have no element of novelty to them.

Driverless cars can take you between train stations and destinations. No magical form of train will come to your house or go to your office.

In fact, this is a perfect use case for driverless cars. The problem with trains everywhere is the wasted time not on the train and the million stops along the way.

Ultimately I think driverless technology can revolutionarise high density public transport too:

It gives us exactingly detailed information on what journeys people need. The dataset will be immensely valuable in allowing the companies that sit on them to first start doing quasi-bus services:

Order a bunch of minibuses. During peak hours, offer an option: Wait for the next dedicated car to be free, or ride share with quicker availability and a discount. Limit detours strictly - there'll be plenty of "Follow road X and pick up 6 people on the way to station Y" type stretches that will make people happy (little time lost; feels efficient if there's not lots of turning off).

Then you can see them partnering with bus providers to dynamically fill in during peak hours, or even bidding for bus franchises and proposing contract changes that would allow for more dynamic, demand-based scheduling.

Ultimately this can feed into planning train type services - companies offering these type of drive share will be able to e.g. let people order "end to end" journeys of the type "pick me up at address 1, get me to address 2" where they show journey options that include rail when it makes sense. The key beying that if they do so, they will know the entire desired journey, and would be able to offer insight into the most efficient interchange locations or other changes to train services would be most desirable.

I really want to be in the business of writing the software that plans these things. The possibilities are crazy. Predicting where to have cars based on overall traffic flows, having cars ready for individuals who always leave at the same time. Think, a car is 30 seconds away every time you follow your routine. That's faster than getting into and starting your own car! Especially if you have a parking garage.

If you're predictable enough, it might be worth it to simply arrive a minute or two ahead of schedule.

The raving reviews you'd get the first times people order a car and are told instantly "your car is already waiting right outside your door" would be rather interesting.

Get in, and your favorite radio station or music is playing.

And for colder climates: Your car is already pre-heated. I remember too many winter mornings during winter in Norway when even ensuring our car would actually start in the morning was an annoyance (even with a garage, space heaters in the garage or motor heaters is sometimes necessary).

> No magical form of train will come to your house or go to your office.

Yes they will; the magic trains you're thinking of are called streetcars. And, with the oddities in oil and the difficulties of maintaining suburbia, we'll be moving back to dense streetcar suburbs soon enough.

Even buses don't take you door to door. I can't imagine a future where a streetcar is anywhere near as good as self driving cars (possibly paired with mass transit).

Are you familiar with streetcar suburbs? They'd have a streetcar running along a commercial street, with residential streets branching off from it; typically one would have a walk of a few blocks from streetcar stop to house. I don't know if a return to that pattern is the future I expect, but it's certainly the one I'm hoping for.

That is only true if the costs of the return trip is free: it isn't. When the car for the guy who arrives downtown at 7am goes back to the suburbs to get the guy who wants to arrive at 8am it is burning nearly as much fuel as it did getting in, and putting just as much wear on the car. The effect is shared cars are more expensive than just a car per person. (Note, this does not account for cost of parking which is a significant factor)

Car sharing (if self-driven) does provide an additional perk--time and money saved trying to find a place to park and paying for that parking. In addition, people turning into parking lots/garages (or worse parallel parking) interrupt the flow of traffic, making congestion worse. There's also many other potential improvements that self-driving cars could use to reduce congestion (faster speeds, reaction times, communication between cars, etc) and greatly lessen the commute during peak times

Wow, so for the short time you have kids in diapers this won't work for you personally. Big whoop.

We still have typewriters around too, and some people ride horses. Old tech doesn't die, it just diminishes to a smaller niche.

"Diapers" is just a synecdoche for parenting equipment: diapers, wipes, books, snacks for older kids, extra changes of clothing, etc.

Car seats will be a bigger problem: they are unwieldy, legally mandated, and require careful installation to be effective. Unlike diapers, even the small boosters used for older children can't fit in a shoulder bag.

A young couple expecting to have children in the next few years might balk at these inconveniences, and that could depress adoption of the 'mobility' model. You have to keep prospective purchasers in mind, who are evaluating their needs over the use-life of a car.