A Tesla with Autopilot engaged accelerated toward a barrier in the final seconds before a deadly crash, an official report into the crash has revealed.
Apple engineer Walter Huang was driving his Model X P100D on a Silicon Valley freeway on the morning of March 23 when the car, under computer control, moved into the triangular space between the main 101 south freeway and an exit ramp on the far left leading to highway 85.
The Autopilot was on, and had been on for 19 minutes, prior to what ended up being a fatal crash as Huang's car drove into the barrier at the intersection at over 70 miles per hour.
Immediately prior to the smash, the Tesla was traveling just below the speed limit of 65 mph, and was following a car ahead of it as Huang traveled on the second-to-left lane of the 101 freeway. The car then started steering toward the highway 85 exit, following the lead of the car ahead of it.
Four seconds before impact, however, the Autopilot in the Tesla was no longer following the lead vehicle and was in the triangular "gore area" that separates the two lanes – one going to the 85, one continuing on the 101.
Then, three seconds before impact and while still in Autopilot mode, the car accelerated – from 62 to 70.8 MPH – before slamming into a partially damaged crash barrier, ultimately killing Huang and causing the front end of his car to be torn off. The car did not recognize any barriers nor carry out any emergency maneuvers or braking.
The Tesla then collided with another two vehicles – a Mazda and an Audi – and the ensuing wreckage brought traffic to a halt. The highway wasn't opened for another six hours while the authorities put out a fire from the Tesla's battery, cleared debris, and towed the car away.
It's also worth noting that the towed Tesla's battery fire required 200 gallons of water and foam to put out. And then five days later – that's five days later – it reignited and had to be put out again.
These are the initial findings [PDF] into the crash as reported this week by the US government's National Transport Safety Board (NTSB).
And what's the 'auto' stand for again?
The reason they are of particular interest is that they raise some serious questions over the safety of Tesla's so-called Autopilot. It should really be called a super-cruise-control because you're not supposed to take your hands off the wheel, nor eyes off the road, when it is engaged – yet encouraged by the name and marketing, owners think it truly is an autonomous driving system and put their lives fully in its hands.
In this specific case, Tesla's knee-jerk defensive approach has been particularly egregious.
As has happened repeatedly, the electric car company immediately sought to blame the driver for the crash, even going to the extraordinary length of releasing its own version of events a week after the crash – something that earned it a formal rebuke from the NTSB.
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Tesla went to some trouble to cast aspersions about Walter Huang. It accepted that its "autopilot" system was engaged, but noted that "the adaptive cruise control follow-distance was set to minimum." (It didn't mention that it decides what that minimum safe distance is allowed to be.)
It also claimed that "the driver had received several visual and one audible hands-on warning earlier in the drive and the driver’s hands were not detected on the wheel for six seconds prior to the collision."
And in a final effort to pin the blame for the crash on Huang, it said: "The driver had about five seconds and 150 meters of unobstructed view of the concrete divider with the crushed crash attenuator, but the vehicle logs show that no action was taken."
All those observations were factually correct but lacked context that has now been partially provided by the NTSB report.
- The warnings highlighted by Tesla had been given a full 15 minutes prior the crash.
- While Huang's hands were not on the steering wheel in the final six seconds before the crash, they were on the wheel when the car started steering to the left. They were also on the wheel for 34 of the 60 seconds prior to the crash.
- While we can assume Huang did not notice the Tesla was in between lanes and heading toward a crash barrier, neither did the Tesla. It was no longer following a vehicle for four of the last five seconds, but instead of braking or maneuvering into one of the two lanes, it actually sped up – past the speed limit – before driving straight into the crash barrier, killing Huang.
There are obviously lots of questions still unanswered, not least of which are:
- What happened to the car that the Tesla was following – did it take the 101 or the 85? That would be critical to understand the car's behavior
- Why did the Tesla speed up rather than slow down?
- Did the Tesla detect it was not in a lane? And if so, why did it not do more to get into one of the actual lanes?
- Did the Tesla know what route Huang was intending to take - the 101 or the 85? And if so, did that affect its behavior?
While the answers to these questions may end up relieving Tesla of blame for the accident, they are just as likely – if not, more likely – to introduce a degree of culpability.
It doesn't help that the car company, through implication and insinuation, seeks to blame everyone but itself for the crash – including the highway authorities when it repeatedly noted that the crash barrier was not in perfect working order because it has been hit in a previous crash and not yet repaired.
The truth – if it isn't immediately apparent to everyone – is that Tesla's "autopilot" is not only not an autopilot, it also doesn't appear to be safe. It was responsible for not only putting Huang's car into a special zone that only exists prior to an intersection but it also actively accelerated within that zone.
It is also worth considering the fact that this piece of freeway is one of the most carefully mapped in the entire world thanks to location right in the heart of Silicon Valley where almost all self-driving and autonomous cars are based and tested.
In short, Tesla has a lot to answer for with this particular crash. Which may explain why, for once, it and its CEO Elon Musk have not said anything about the report yet. ®