One of the great things about a fleet like this would be that you could change your car depending on where you were going and what you were doing. For example you take a 1-seater to get around a city but if you go a longer drive you take a larger, more powerful car. This is one of the things I enjoy about using zipcar, you get to drive fancy cars some days but only pay for the cheaper ones most of the time.

The great thing about an automated fleet is that you could actually switch cars during the journey. Take a small car to leave the busy urban areas and than switch to a larger car when you get to the motorway.

I love the idea of smaller, more efficient vehicles, but I think we hold too much hope in the fact that they could be "self driving". Why would a smaller self-driving car be more likely to gain in popularity over what most people choose to drive today? Why is it more likely to be electric? Those are two independent characteristics that haven't taken off on their own; I don't see how the self-driving aspect is going to change many of the existing problems we have with car-based transportation.