Autonomous driving is the automotive buzz-phrase of the moment as we head inexorably to a future where cars will self-pilot themselves. It’s estimated that robotised cars will account for up to a quarter of vehicle sales in 20 years’ time.

Many new cars twirling on today’s motor show stands are being launched with some level of autonomous driving ability, edging closer to an end-game where we can one day let the car ‘take the wheel’. Imagine how less stressful rush-hour commutes would be if your car could guide itself through the gridlock while you sit back and read a book, watch a movie, or take a nap.

But there are a few stepping stones before we reach this utopian ideal and completely entrust our transport needs to artificial intelligence. For now we have cars that are able to accelerate, brake, and steer by themselves in certain situations, but always require some driver input.

The newly-launched Audi A8 I drove at the world launch in Spain recently takes us halfway to full self-driving by becoming the first volume production car to have Level 3 autonomy. But what exactly does that mean?

To guide us through the various levels of self-driving ability, a six-level classification system has been devised by the Society of Automotive Engineers (SAE), explained as follows:

Level 0: No automation

The human does all the work.

Level 1: Driver assisstance

The car performs a simple task like cruise control, and maintains a speed chosen by the driver.

Level 2: Partial automation

The car helps out with more than one task, assisting with both steering and acceleration/deceleration. The car can maintain its speed, slow down to avoid other cars or pedestrians, and stay in its lane. Several production cars already have this technology. It started with luxury vehicles but has filtered down into more mainstream cars.

Level 3: Conditional automation

The car can make more complex decisions. Instead of braking to avoid hitting a suddenly-stopped minibus taxi, it can look around, decide to change lanes, and pass (until the next minibus cuts it off). The human driver still needs to take over in certain cases, for instance if the road’s painted lines disappear.

Level 4: High automation

The car can handle any driving situation by itself in most environments, even if the human driver doesn’t respond to a request to intervene.

Level 5: Full automation

No steering wheel needed. Tell the car “take me home” and sit back and snooze while the car navigates its way through the traffic.

Legal hurdles

The abovementioned Audi A8, with its Level 3 autonomy, is able to assume full driving control in stop-and-go traffic at up to 60km/h, but this so-called Traffic Jam Pilot system will only be introduced as different countries’ laws allow for it. Before we set robotised cars loose on the world, there’s a wide range of legal and ethical questions to be answered.

For instance, in an impending collision, would a self-driving car choose to crash into a pedestrian walking next to the road, or into a motorcyclist that had turned across its path?

And who is responsible if a crash does occur: the person inside the car, the vehicle owner, or the company that built it? And there will have to be cast-iron safeguards to prevent a car’s computer potentially being hacked.

It’s a complex issue and one that’s occupying scientists and philosophers alike.

Since robots can’t act like humans or be treated like them, we must clarify how to assign our criteria from criminal law, civil law and common morals to the new technologies.

Several carmakers have also teamed up to create a 32-acre “city” at the University of Michigan in the United States, where self-driving and wirelessly connected cars are being tested before they are unleashed onto public roads.

Dubbed Mcity, the facility simulates the chaos of a busy urban environment with a range of complexities vehicles encounter. It includes roads with intersections, traffic signs and signals, pavements, traffic circles, simulated buildings, street lights, and obstacles such as construction barriers.

Maybe they could add some South African minibus taxis to the mix as well, if they really want a real-life challenge.