Driverless is not a new thing – many millions of passenger journeys are completed this way every year on trains and metros. And most of the time when you are a passenger on a plane you are in the hands of the auto-pilot!
So what is the big deal with driverless cars? It is simply this – roads are a more complex environment than a flight path or rail network. Driverless cars, taxis, buses, lorries and the like will only become a reality when they can cope with the complexity.
Most of that complexity is brought about by having drivers and pedestrians sharing the road space at the same time.
In rail systems, where other trains and potentially vehicles crossing the tracks (or passengers falling onto the tracks) is an issue different levels of automation have been designed – some trains rely on a guard to open and close the doors only, others require the guard to oversea the track ahead as well.
Perhaps this gives the best clues as to how driverless cars should operate for now – on roads where there is least complexity then the car is truly driverless but where the roadscape is judged to get more complex then a driver must take more control.