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Sure sounds like the Ford was following the observer car, probably pretty closely for the given speed. Having reflectors on the stationary car isn't useful when

Sure sounds like the Ford was following the observer car, probably pretty closely for the given speed. Having reflectors on the stationary car isn't useful when the stationary car is completely obscured by the observer car. If the observer car missed it by only a couple of seconds, there was probably only five seconds or so for the Ford driver to see it, realize what was happening, and properly respond. And at those speeds and that kind of distance, braking probably wasn't an option especially if you've already burned a second and a half just realizing "oh shit that's a stopped car". I haven't heard either way if there was significant braking by the Ford or not, going on an open Texas highway typically means they were probably going >80mph as the posted speed was probably 80mph. I'm not sure exactly which stretch of I-10 they were on, but a lot of it around San Antonio (especially the unlit stretches) are posted 80. Even if they slammed on the brakes and managed to cut half their speed they're still slamming into a stationary, heavy object at 40ish mph. I imagine it pretty much is an instance of following too closely and going too fast for the lighting conditions for the possibility of suddenly encountering a completely stopped object in the road. I agree, its a bad limitation of "self driving" systems, but in the end I imagine the average human would have probably had a similar following distance and also be travelling at a similar speed. The Ford system does track attentiveness and will drop out of bluecruise mode and bring the car to a stop if the driver isn't paying attention. It does a lot of gaze tracking with IR lights and cameras. Its not like on some cars where attaching a little weight to the wheel is enough to fake attention. The driver was paying attention to the road, at least within the last few seconds. EDIT: Sounds like the stretch in question is a 70mph area. Still, I imagine on an open highway and how loads of Texans drive, they were probably going about 80mph. Also, it does appear this section of I-10 does have roadway lighting. FWIW, I've seen lots of cars slam into the back of a stopped car on a highway in bright daylight conditions without the assistance of driving aids. My old office had a pretty good view of a long stretch of a major 70mph highway; I saw a lot of collisions. Meatbag drivers are pretty terrible.

BobaFloutist 3y ago
> Sure sounds like the Ford was following the observer car, probably pretty closely for the given speed. Having reflectors on the stationary car isn't useful when the stationary car is completely obscured by the observer car. If the observer car missed it by only a couple of seconds, there was probably only five seconds or so for the Ford driver to see it, realize what was happening, and properly respond. Sounds like the Ford wasn't maintaining a safe following distance.
- vel0city 3y ago
  I agree. Maybe these driving aids should force better following distances and max speeds when its dark outside, especially if it ultimately relies on human vision to properly detect and react to a stopped object. I'd still say a human would probably have also had an unsafe following distance and speed in this scenario.
  - BobaFloutist 3y ago
    A human would have likely driven unsafely too, but human behaviors don't scale as predictably, so I think it's appropriate to hold them to a lower bar. If a self driving car (or driving aid at least) behaves unsafely in some consistent way, that could cause far more accidents than the "typical human driver" typically behaving in that unsafe way. It's frankly outrageous to me that it's literally possible for automated or assisted driving to fail such a common-sense, basic rule of road safety as following distance. And that's my real concern with self-driving cars (apart from considering them a competitor to the public transit I'd rather see), that it doesn't feel like there's a sufficient baseline level of caution for their bread-and-butter behaviors.
- kwhitefoot 3y ago
  At 80 mph there should be about 100 m distance between vehicles to maintain the recommended 3 seconds separation. 80 mph is 36 m/s. I drive with traffic aware cruise control always on maximum separation (Tesla S), but hardly anyone else abides by the recommendation. Even 1 second separation is 7 car lengths at that speed.
toast0 3y ago
Thanks for the link elsewhere. While I agree with your assessment about what probably happened, I still say there aren't many facts. It would be helpful to know how far in advance the observer changed lanes. > Even if they slammed on the brakes and managed to cut half their speed they're still slamming into a stationary, heavy object at 40ish mph. A 40 mph collision is often survivable these days (that's the speed used for crash tests!). The accident vehicle driver survived regardless; the driver of the stopped car didn't though. Driver assistance is really unhelpful in these situations. Most likely the lead car slowed down, at least a bit while changing lanes, so an active driver would also be slowing and may be quicker to slow more when an unexpected car is there, but driver assistance is going to see the lead car left the lane and there's no other cars (because stationary objects are ignored) so go ahead and speed up. Tesla's are known to have a very high rate of acceleration in this case, not sure about the acceleration for the MachE. Adding more speculation: as an untrained armchair internet crash investigator, my guess is the collison happened at over 40 mph. The IIHS crash test [1] seems to show less damage than the accident vehicle, and the stopped vehicle was overturned in addition to significant damage. [1] https://m.youtube.com/watch?v=Po_QfX5U8lI&pp=ygUXbWFjaCBlIGNyYXNoIHRlc3QgZnJvbnQ%3D https://m.youtube.com/watch?v=Po_QfX5U8lI&pp=ygUXbWFjaCBlIGN...
- vel0city 3y ago
  I do agree there's a certain level of variability in the possibilities of what actually happened with the facts given so far. I'd really like to see a video recording of what happened so we can actually judge the possible reaction time for the Ford driver. I totally acknowledge its possible there was many seconds between the observer car leaving the lane and the Ford colliding; it is a pretty straight stretch of road so the observer could have seen the car for a bit. Within the unknowns of this incident, it is possible a human without ADAS systems in use here could have responded better. But to me, with what I'm reading about it and my past experiences of watching drivers on Texas highways hitting stopped cars in broad daylight, I imagine a lot of humans would have hit the car in a lot of the possible scenarios.

BobaFloutist 3y ago

> Sure sounds like the Ford was following the observer car, probably pretty closely for the given speed. Having reflectors on the stationary car isn't useful when the stationary car is completely obscured by the observer car. If the observer car missed it by only a couple of seconds, there was probably only five seconds or so for the Ford driver to see it, realize what was happening, and properly respond. Sounds like the Ford wasn't maintaining a safe following distance.

vel0city 3y ago
I agree. Maybe these driving aids should force better following distances and max speeds when its dark outside, especially if it ultimately relies on human vision to properly detect and react to a stopped object. I'd still say a human would probably have also had an unsafe following distance and speed in this scenario.
- BobaFloutist 3y ago
  A human would have likely driven unsafely too, but human behaviors don't scale as predictably, so I think it's appropriate to hold them to a lower bar. If a self driving car (or driving aid at least) behaves unsafely in some consistent way, that could cause far more accidents than the "typical human driver" typically behaving in that unsafe way. It's frankly outrageous to me that it's literally possible for automated or assisted driving to fail such a common-sense, basic rule of road safety as following distance. And that's my real concern with self-driving cars (apart from considering them a competitor to the public transit I'd rather see), that it doesn't feel like there's a sufficient baseline level of caution for their bread-and-butter behaviors.
kwhitefoot 3y ago
At 80 mph there should be about 100 m distance between vehicles to maintain the recommended 3 seconds separation. 80 mph is 36 m/s. I drive with traffic aware cruise control always on maximum separation (Tesla S), but hardly anyone else abides by the recommendation. Even 1 second separation is 7 car lengths at that speed.

toast0 3y ago

Thanks for the link elsewhere. While I agree with your assessment about what probably happened, I still say there aren't many facts. It would be helpful to know how far in advance the observer changed lanes. > Even if they slammed on the brakes and managed to cut half their speed they're still slamming into a stationary, heavy object at 40ish mph. A 40 mph collision is often survivable these days (that's the speed used for crash tests!). The accident vehicle driver survived regardless; the driver of the stopped car didn't though. Driver assistance is really unhelpful in these situations. Most likely the lead car slowed down, at least a bit while changing lanes, so an active driver would also be slowing and may be quicker to slow more when an unexpected car is there, but driver assistance is going to see the lead car left the lane and there's no other cars (because stationary objects are ignored) so go ahead and speed up. Tesla's are known to have a very high rate of acceleration in this case, not sure about the acceleration for the MachE. Adding more speculation: as an untrained armchair internet crash investigator, my guess is the collison happened at over 40 mph. The IIHS crash test [1] seems to show less damage than the accident vehicle, and the stopped vehicle was overturned in addition to significant damage. [1] https://m.youtube.com/watch?v=Po_QfX5U8lI&pp=ygUXbWFjaCBlIGNyYXNoIHRlc3QgZnJvbnQ%3D https://m.youtube.com/watch?v=Po_QfX5U8lI&pp=ygUXbWFjaCBlIGN...

vel0city 3y ago
I do agree there's a certain level of variability in the possibilities of what actually happened with the facts given so far. I'd really like to see a video recording of what happened so we can actually judge the possible reaction time for the Ford driver. I totally acknowledge its possible there was many seconds between the observer car leaving the lane and the Ford colliding; it is a pretty straight stretch of road so the observer could have seen the car for a bit. Within the unknowns of this incident, it is possible a human without ADAS systems in use here could have responded better. But to me, with what I'm reading about it and my past experiences of watching drivers on Texas highways hitting stopped cars in broad daylight, I imagine a lot of humans would have hit the car in a lot of the possible scenarios.