With shared resources, this might not be the case.

Today, car owners have already spent $x on their cars -- so they have an incentive to use their investment to the fullest.

Compare that with a shared-car system like ZipCar. ZipCar is generally much more efficient than owning a vehicle (if you don't use it to commute) -- however, since you pay per hour, you have an incentive to skip the car when it's not necessary.

By removing the sunk-costs of ownership, you could incentivize conservation rather than consumption.

Maybe - I wonder just how elastic the miles-traveled vs convenience curve is.

There is surely an upper bound to how much traveling any person wants to do. If it were 5% more convenient for me to travel by car, I _might_ travel 5% more, but I couldn't see myself traveling 50% or 100% more no matter _how_ convenient you could make that travel.

With ZipCar, you have to first get to the car, and then also get back from the car. For most people, the car they own is in their driveway or parking spot.

With a model more like Car2Go (pick up the car wherever you can find one, leave it wherever you want to) this isn't as much of an issue. In Austin there's pretty much always a car within a few blocks... almost "driveway-level" accessibility.

And if even 10% of drivers switch to using this model, then there's always going to be a car on your block. That's pretty competitive.

With driverless cars it's even less of an issue, because the car will literally drive from the end of the block (where it's waiting) to your door.

Thanks, I wasn't aware of Car2Go. Their price rates http://www.car2go.com/sandiego/en/affordable-rates/ might give a good idea about how expensive using a driverless car would be if it existed today.

Assuming, that the San Diego prices can be applied to Francisco, it seems like taking such a car from downtown to the airport would be about the same as the BART subway. I assume, that would be too expensive for a daily commute.

> With ZipCar, you have to first get to the car, and then also get back from the car.

But with a self-driving car, you'd skip both steps. Instead, you'd ask for the car and step out in your driveway when you get an alert that it's here.

I know. I am illustrating why conclusions about ZipCar aren't going to apply 100% to a self-driving car.

With a self driving car, it would be like a taxi. It would come to your driveway when you need it.

Well fuel is still not free. In the U.K. at least you would hesitate due to the high cost (much lower in U.S.).