If online dashcam videos have taught me one thing, it's that some drivers will do almost anything to avoid an accident, other than fully depressing their brake pedal while traveling in a straight line.
Selection bias? Dashcam videos showing normal braking and the clear, preemptive avoidance of an accident would be the least uploaded/promoted and watched?
A car in the back also, if you brake, you very much take the risk of getting hit by the car in the back because these idiots are pushing in your ass :/
It's possible he didn't see the train in time to fully stop.
Braking is important but steering to avoid something is probably the better option in most cases. It takes some distance to stop a fast traveling, heavy vehicle.
Imagine seeing an accident happen directly in front of you on the highway. You better be able to steer in time cause you sure aren't stopping before hitting anything.
This is also the reason to try and have both hands on the steering wheel all of the time, versus a relaxed one hand at 12 o'clock lounge while doing 70+ mph.
Radar would probably not, in this case. At the point where it crossed the road the train was not moving toward or away from the car, so radar would have to filter it out as a stationary object (stationary objects have to be aggressively filtered with radar to avoid false positives from metal signs or stopped cars near the road). Even if it somehow was detected as a moving object, sometimes trains stop in crossings, at which point it would definitely be a stationary object and radar would be useless.
Fog (small water droplets suspended in air) is transparent to light but it can reflect it if
the wavelength of light is smaller than the water droplet diameter. Since there are so many droplets it scatters light making lidar useless.
The usual diameter of fog droplets is in the micrometer range, but is highly variable.
So microwave/milimeterwave lidar could theoretically work.
I thought it must be one of those situations where the train was around the corner and even most humans wouldn't see it unless they stopped and listened like they're supposed to. Then I watched the video. I would have missed it at that speed in the fog, but I wouldn't drive that fast in the fog.
The signal is clear enough at a safe speed, but there wasn't much time to react zooming around inside a cloud.
Really? I wouldn't have missed. There was plenty of time for the car to stop based on the video I saw. It looks like 4 seconds of visibility before the driver had to turn the car. It didn't seem like the car was going that fast. There's no way a normal human being paying attention wouldn't be able to get the car to a full stop in that 4 seconds.
From what I understand, Tesla's FSD only uses vision to drive. But we, as humans, use all of our senses to drive. We use vision, smell, sound, as well reasoning and historical knowledge.
If I saw flashing lights in a fog, I would slow down no matter what. I might have heard some sounds, however faint, from the train moving. I would have reasoned that I should always drive slow in the fog, particularly near an area where there are train tracks. I might have sensed that we are driving in train track territory because I saw some tracks around here in the past or I have come across knowledge about this area before that I remembered. Tesla's FSD uses non of these senses.
Flashing light means you have to stop according to the official rules (at least where I am from). That’s because trains can go much faster than what people think and can hit you out of nowhere.
> Doty said the car nearly hit a moving train in November after it approached some tracks after a sharp turn.
> He said that the Tesla did not slow down but that he was able to stop, still hitting the crossbar and damaging his windshield.
So this guy has been in a similar position before and still let the car barrel towards the train hoping it would stop this time? I don’t buy his story.
The fog is an interesting situation too, as non-vision technologies would struggle here too.
Overlooking the train is one thing, but overlooking the red flashing lights at the railway crossing that were clearly visible in the video is another thing entirely...
But isn't Elon telling the story that it improves overtime from month to month. So you may would have expected that it have learned since November, which is more than 3 month in the past.
Automotive radars struggle to detect objects which are not moving relative to the ground in the range direction. Such detections must be filtered aggressively to avoid false positives from stationary objects such as metal signs near or above the road.
At the point where it crossed the road the train was moving sideways relative to the car. In the range direction it was close to stationary relative to the ground (and the crossing arm was entirely stationary, of course). So I think radar would be unlikely to save this case. If the radar was looking to the side, so it could see the train cars approaching at high speed and predict that they would enter the road, then maybe. But this seems like it would also potentially have a lot of false positives e.g. at overpasses. Perhaps for that reason, I believe automotive radars like the ones Teslas used to have generally only point toward the front. And if the train had been stopped in the crossing, as they sometimes are, the radar would be unhelpful no matter where it was pointed.
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Braking is important but steering to avoid something is probably the better option in most cases. It takes some distance to stop a fast traveling, heavy vehicle.
Imagine seeing an accident happen directly in front of you on the highway. You better be able to steer in time cause you sure aren't stopping before hitting anything.
This is also the reason to try and have both hands on the steering wheel all of the time, versus a relaxed one hand at 12 o'clock lounge while doing 70+ mph.
Radar would, but radar is also a bit crap - in particular angular resolution is very very poor.
The usual diameter of fog droplets is in the micrometer range, but is highly variable.
So microwave/milimeterwave lidar could theoretically work.
The signal is clear enough at a safe speed, but there wasn't much time to react zooming around inside a cloud.
Really? I wouldn't have missed. There was plenty of time for the car to stop based on the video I saw. It looks like 4 seconds of visibility before the driver had to turn the car. It didn't seem like the car was going that fast. There's no way a normal human being paying attention wouldn't be able to get the car to a full stop in that 4 seconds.
From what I understand, Tesla's FSD only uses vision to drive. But we, as humans, use all of our senses to drive. We use vision, smell, sound, as well reasoning and historical knowledge.
If I saw flashing lights in a fog, I would slow down no matter what. I might have heard some sounds, however faint, from the train moving. I would have reasoned that I should always drive slow in the fog, particularly near an area where there are train tracks. I might have sensed that we are driving in train track territory because I saw some tracks around here in the past or I have come across knowledge about this area before that I remembered. Tesla's FSD uses non of these senses.
> He said that the Tesla did not slow down but that he was able to stop, still hitting the crossbar and damaging his windshield.
So this guy has been in a similar position before and still let the car barrel towards the train hoping it would stop this time? I don’t buy his story.
The fog is an interesting situation too, as non-vision technologies would struggle here too.
At the point where it crossed the road the train was moving sideways relative to the car. In the range direction it was close to stationary relative to the ground (and the crossing arm was entirely stationary, of course). So I think radar would be unlikely to save this case. If the radar was looking to the side, so it could see the train cars approaching at high speed and predict that they would enter the road, then maybe. But this seems like it would also potentially have a lot of false positives e.g. at overpasses. Perhaps for that reason, I believe automotive radars like the ones Teslas used to have generally only point toward the front. And if the train had been stopped in the crossing, as they sometimes are, the radar would be unhelpful no matter where it was pointed.