Communications of the ACM

tended to give the game away. However, now that the technology is shrinking and autonomous cars are starting to look more normal, it will become increasingly difficult to know when a car is being driven autonomously. There is also a reverse argument. Suppose autonomous vehicles are (or become) better drivers than humans. Then just like today when we demand less experienced and capable learner drivers are identified, we might demand that human drivers are identified apart from autonomous drivers. A Turing Red Flag law will achieve this.

Let’s move on to the second area where a Turing Red Flag law might start having impact shortly. Consider virtual assistants like Apple’s Siri or Microsoft’s Cortana. Here is a recent conversation I had with Siri:

Siri. What can I help you with?

Q. Are you a computer?

Siri. I can neither confirm nor deny my current existential status.

Q. Are you a human?

Siri. I’m an assistant. That’s all that matters.

Q. Are you an AI?

Siri. That’s a rather personal question.

Based on conversations like these, it would appear that Siri is coming close to violating this proposed Turing Red Flag law. It begins its conversations without identifying itself as a computer, and it answers in a way that, depending on your sense of humor, might deceive. At least, in a few years time, when the dialogue is likely more sophisticated, you can imagine being deceived. Of course, few if any people are currently deceived into believing that Siri is human. It would only take a couple of questions for Siri to reveal that it is not human. Nevertheless, it is a dangerous precedent to have technology like this in everyday use on millions of smartphones pretending, albeit poorly, to be human.

There are also several more trusting groups that could already be deceived.

My five-year-old daughter has a doll
that uses a Bluetooth connection to Siri
to answer general questions. I am not
so sure she fully appreciates that it is
just a smartphone doing all the clever
work here. Another troubling group are
patients with Alzheimer’s disease and
other forms of dementia. Paro is a cud-
dly robot seal that has been trialed as
indeed stop, and so save us from having
to brake hard to avoid an accident. As a
second example, if an autonomous car
is driving in front of us in fog, we can
suppose it can see a clear road ahead us-
ing its radar. For this reason, we do not
have to leave a larger gap in case it has
to brake suddenly. As a third example, at
a four-way intersection, we can suppose
an autonomous car will not aggressively
pull out when it does not have right of
way. And as a fourth and final example,
if an autonomous car arrives at a diver-
sion, we might expect it to drive more
slowly as it tries to work out where the
road is now going.

How should an autonomous vehicle identify itself? I don’t suppose this should be with a person walking in front with a red flag. This was too restrictive even back in 1865. Autonomous vehicles might have to carry distinctive plates, just like we require learner drivers to identify themselves on the roads today. Or autonomous vehicles might have to display a magenta flashing light whenever they are being operated autonomously. In addition, autonomous vehicles should broadcast their location, velocity, and autonomy to neighboring vehicles.

In June 2015, Reuters reported that two autonomous cars, one from Google and the other from Delphi Automotive Plc, nearly had an accident on a Silicon Valley street. The Google car apparently cut off the Delphi car as it was about to perform a lane change. The Delphi car then had to take “ appropriate action” to avoid an accident. Clearly, it would help prevent such incidents if autonomous vehicles were required to broadcast their location and intentions. Of course, adequate safeguards will also need to be put in place that such broadcasting does not compromise the privacy of their human occupants.

Once autonomous vehicles are commonplace, other motorists will expect to meet autonomous vehicles. But before this time, it will be important to know that the oncoming vehicle is somewhat special and may behave differently to a human driver. In the past, it was less necessary for autonomous vehicles to identify themselves. There were few of them and most looked a little odd. The presence of large rotating LIDAR sensors on their roofs has