Uncertain roadWith such technology already on the road and prototypes like BMW’s in the works, it’s tempting to imagine that total automation can’t be far away. In reality, making the leap from the kind of autonomy in the Mercedes-Benz S-Class to the kind in BMW’s prototype will take time, and the dream of total automation could prove surprisingly elusive.

For one thing, many of the sensors and computers found in BMW’s car, and in other prototypes, are too expensive to be deployed widely. And achieving even more complete automation will probably mean using more advanced, more expensive sensors and computers. The spinning laser instrument, or LIDAR, seen on the roof of Google’s cars, for instance, provides the best 3-D image of the surrounding world, accurate down to two centimeters, but sells for around $80,000. Such instruments will also need to be miniaturized and redesigned, adding more cost, since few car designers would slap the existing ones on top of a sleek new model.

Cost will be just one factor, though. While several U.S. states have passed laws permitting autonomous cars to be tested on their roads, the National Highway Traffic Safety Administration has yet to devise regulations for testing and certifying the safety and reliability of autonomous features. Two major international treaties, the Vienna Convention on Road Traffic and the Geneva Convention on Road Traffic, may need to be changed for the cars to be used in Europe and the United States, as both documents state that a driver must be in full control of a vehicle at all times.

Most daunting, however, are the remaining computer science and artificial-­intelligence challenges. Automated driving will at first be limited to relatively simple situations, mainly highway driving, because the technology still can’t respond to uncertainties posed by oncoming traffic, rotaries, and pedestrians. And drivers will also almost certainly be expected to assume some sort of supervisory role, requiring them to be ready to retake control as soon as the system gets outside its comfort zone.

Good points, but let's still take a moment to be amazed that we've started down this road.

To me a self-driving car is the one, which does not have a driver seat. Same way as iPhone does not have a physical keyboard. It should drive with or without me. It should drop me off at the entrance and then go find parking. Everything else is driver assistance, not self-driving.

Yes, preferably we can hollow out the inside to make room for a couch, so I can sleep or surf the Internet while I'm being driven around. That would be ideal.

Wow, a LOT of car makers are into this:

Why are Prius and Lexus listed as Google not Toyota?

I don't want to wait until 2020 to go driverless!

I suppose the "self-driving" car of 2013 is Uber?

I can imagine that Uber will one day offer driverless cars.