> A golf cart is just fine for going 5-10 miles in urban traffic.

I hadn't thought of this. Imagine Google buying garages all over NYC and filling them with driverless Smart cars (or similar). A button is added to your phone's Google Maps app, so that in addition to "Get Directions" and "Navigate", you also have the option of "Pick Me Up".

So, you search for where you want to go on Google Maps and tap "Pick Me Up", with the option of telling it how many people are in your party. Within 5 minutes enough Smart cars for your party stop within 20 feet of you, even if you've already started walking, thanks to your phone's GPS. You get in the car, which has no steering wheel, and touch "Go" on the in-dash touch-screen to start the car driving to your destination.

I could get used to that.