When can you buy one?

Mercedes-Benz, BMW and Tesla already have semi-autonomous models you can buy today. These cars allow users to follow traffic in front of them with minimal steering input from the driver.

Next year, Volvo will launch its S90, which can go on semi-autonomous mode on highways and will not need a vehicle in front to track.

But whether the cars can be driven hands-free depends on rules in each country. Like many cities, Singapore is studying how the law has to be amended. For instance, if a robotic is involved in a fatal accident, is the person at the helm, previously the driver, absolved of all liability?

Some policymakers are embroiled in an ethical debate on the topic. They ask if a computer program can or should be empowered to decide who lives in a dire situation. In the hypothetical "trolley problem", a runaway tram will hit one of two groups of people, depending on a person who is able switch the track.

But experts dismiss this fear, saying that even the best human driver would not be able to decide. So why should a machine be expected to?

In any case, a driverless car that can navigate on its own completely on all roads is at least 10 years away.

Christopher Tan

Join ST's WhatsApp Channel and get the latest news and must-reads.

A version of this article appeared in the print edition of The Straits Times on December 11, 2015, with the headline When can you buy one?. Subscribe