The world has had its first self-driving car fatality: a Tesla autopilot
failed. So far the world hasn’t freaked out. I think
self-driving cars will be way safer than human-driven
cars. But there’s a lot of shaping the truth in Tesla’s
announcement.
(Fair warning: this blog post is uninformed hot take
territory. I’m reacting to Tesla’s description of the crash,
published two months after the death. We’ll know a lot more after
an independent investigation.)
Tesla’s press release is masterful. It characterizes the cause
of the accident like this:
the vehicle was on a divided
highway with Autopilot engaged when a tractor trailer drove across the
highway perpendicular to the Model S. Neither Autopilot nor the driver
noticed the white side of the tractor trailer against a brightly lit
sky, so the brake was not applied.
A truck pulled out in
front of the car on the highway. It may well have been an unavoidable
accident. We’ll know eventually.
But note the facility of claiming the “driver” didn’t
notice the truck. How do we know that? The man is dead, we have no idea
what he saw. I don’t know about you, but I’ve never once failed to spot
a white truck against a bright sky, particularly when I’m driving towards it
at 70mph. I could see how a computer vision system would fail that test though.
“The brake was not applied”. It takes time to
apply the brakes after you see your death coming at you. Doubly so if
you’re not actually driving. The passenger-behind-the-wheel was
almost certainly not having his foot hovering gently near the accelerator
/ brake like an engaged driver would. That slows reaction time. I do
this all the time with my simple cruise control and it scares the hell
out of me when some slow jerk pulls in front of me and I don’t react quickly.
(I also admire the comfort of “he never saw it
coming”. Sort of takes the sting out of the next sentence, which
describes the unfortunate’s grisly decapitation.)
The real problem here is Tesla’s autopilot is a half measure,
“driver assist”. It doesn’t fully drive the car. This
design is the most dangerous of all worlds. I had this experience with my
airplane’s autopilot all the time. At some point when the automation
does enough work, you can’t help but check out mentally, let the
machine take over. But if the machine isn’t capable of taking over
entirely you can end up dead.
That’s why I’m in favor of fully autonomous vehicles. No
steering wheel, no accelerator, maybe just a single brake or other
emergency cutout. Of course in this situation the software has to work reliably.
Let’s say a fatality rate of 50% of human drivers. And insurance and the law
have to adapt to this shift of control to software.
I believe
the technology nerds are very close to having systems that can fully
drive a car with no “driver assist” ever needed, at least
in clear weather. It will be a better future. And those robot cars will
kill some of their passengers. Far fewer than humans are killing now.