NTSB: Autopilot steered Tesla car toward traffic barrier before deadly crash
NTSB:• At 8 seconds prior to the crash, the Tesla was following a lead vehicle and was traveling about 65 mph.• At 7 seconds prior to the crash, the Tesla began a left steering movement while following a lead vehicle.• At 4 seconds prior to the crash, the Tesla was no longer following a lead vehicle.• At 3 seconds prior to the crash and up to the time of impact with the crash attenuator, the Tesla’s speed increased from 62 to 70.8 mph, with no precrash braking or evasive steering movement detected.This is the Tesla self-crashing car in action. Remember how it works. It visually recognizes rear ends of cars using a BW camera and Mobileye (at least in early models) vision software. It also recognizes lane lines and tries to center between them. It has a low resolution radar system which ranges moving metallic objects like cars but ignores stationary obstacles. And there are some side-mounted sonars for detecting vehicles a few meters away on the side, which are not relevant here.The system performed as designed. The white lines of the gore (the painted wedge) leading to this very shallow off ramp become far enough apart that they look like a lane.[1] If the vehicle ever got into the gore area, it would track as if in a lane, right into the crash barrier. It won't stop for the crash barrier, because it doesn't detect stationary obstacles. Here, it sped up, because there was no longer a car ahead. Then it lane-followed right into the crash barrier.That's the fundamental problem here. These vehicles will run into stationary obstacles at full speed with no warning or emergency braking at all.  That is by design. This is not an implementation bug or sensor failure. It follows directly from the decision to ship "Autopilot" with that sensor suite and set of capabilities.This behavior is alien to human expectations. Humans intuitively expect an anti-collision system to avoid collisions with obstacles. This system does not do that. It only avoids rear-end collisions with other cars.  The normal vehicle behavior of slowing down when it approaches the rear of another car trains users to expect that it will do that consistently. But it doesn't really work that way. Cars are special to the vision system.How did the vehicle get into the gore area? We can only speculate at this point. The paint on the right edge of the gore marking, as seen in Google Maps, is worn near the point of the gore. That may have led the vehicle to track on the left edge of the gore marking, instead of the right. Then it would start centering normally on the wide gore area as if a lane. I expect that the NTSB will have more to say about that later. They may re-drive that area in another similarly equipped Tesla, or run tests on a track.[1] https://goo.gl/maps/bWs6DGsoFmD2