Driverless Cars?

Some may say that's the problem. Too many cars these days don't have drivers at least people driving that have a mind hence Driverless.

Seriously when I first started using SatNav it occurred to me that if it could be hooked up to a computer controlling the car it could take you from A to B. However it needs very good GPS tracking down to feet, otherwise where would the car go. Delivery drivers use their SatNavs and can't find us. They are a couple of miles off and ave to ring us "where are you?"they say. How would that work if the car  was driving?