Model X Crash on US-101 (Mountain View, CA)

[PhantomX]

Strange indeed.
As an engineer do you think it’s plausible that the car did a front somersault (as reported) over the leading edge of the battery (the low down but foremost really strong point). With the front bumper beam / motor embedded in the barricade the front end would be pulled off while it somersaulted? The front end would have been designed to be much stronger in compression than tension.

It's aluminum though, so tensile and compressive strengthes are nearly identical. I can see most of the dashboard components being pulled apart if the front did get stuck in the barrier, but I am having a hard time seeing the unibody sustain the damage it did by a tensile load.

 

[TEG]

I just drove this today, the left most carpool lane is preferable when the speed differential is large. I find it more comfortable to have the #2 carpool lane to my right, even when it is empty, when going at high speed; you are less likely to be cutoff by a car jumping into the lane from the slow moving traffic. During my drive this afternoon it was clear that most drivers also preferred the left most carpool lane, so much so the right carpool lane was almost empty. This accident was on my mind and I moved to the #2 carpool lane a little earlier than I probably normally would have. But then I had to go into into hyper vigilant mode since I was zooming by the slow non-carpool traffic. I found myself slowing down because the speed differential was so large.

That sounds like people are being guided to play "chicken" where they go onto the 85 offramp for a while to go faster than the carpool on the right, then cut across the gore area at the last minute to get into the correct carpool lane. If someone tried to cut it close and hit the smart cushion rails it could drag them into the wall. This had been speculated before, but the suggestion that the left carpool flows better than the right gives new reason why people might be doing that more. And again we are back to the thought that there should be candelstick delineators (plastic poles) in the gore area to discourage people from doing that.

 

[buttershrimp]

Not necessarily if you’ve driven this a few times. Although it’s generally reverse commute at that time of day (though less than the total gridlock of the other direction it is still bad) even if you intend on staying south on 101 many drivers are attracted to the emptier far left commute lane for as long as you can - and so end up cutting right. Even if you aren’t aggressively focused on speed it’s pretty easy to zone out and follow the left white stripe and end up in the wrong lane.

So far we have no information on whether AP was engaged so let’s not get distracted by that. My biggest concern is whether the exposed rails of the already compressed barrier would guide a car to its demise as a couple others have mentioned.

Yeah I'm not sure since I don't know this area.... I guess I wonder if he could have been in the far left HOV lane that was about to turn into 85. Charting his daily path would be most helpful.

My two options -
He was in the 101 south HOV lane and something or AP caused him to swerve into the barrier. The idea of it gradually drifting into the barrier makes sense only if he was not paying attention. He knew the road so he would have seen AP drift off line.

He was in the 85 south HOV exit using AP and didn't notice he was about to take the wrong HOV lane. This would have only happened if he was not paying attention. I have seen many people become to reliant on AP and forget they should be driving.

It looks to me like he was in the 85 south HOV lane but that is not the lane he would need to take to get to work. That is the part that does not make sense to me.

This is my scenario I'm imagining at this time. Only if he would have been benefiting from the HOV lane for a while and then routinely exits to get back on the 101.

 

[buttershrimp]

That sounds like people are being guided to play "chicken" where they go onto the 85 offramp for a while to go faster than the carpool on the right, then cut across the gore area at the last minute to get into the correct carpool lane. If someone tried to cut it close and hit the smart cushion rails it could drag them into the wall. This had been speculated before, but the suggestion that the left carpool flows better than the right gives new reason why people might be doing that more. And again we are back to the thought that there should be candelstick delineators (plastic poles) in the gore area to discourage people from doing that.

YEs that's my theory too without seeing the area.

 

[TEG]

I just noticed this from another fatal crash after hitting the same smart cushion in 2015:
Driver dies in Hwy. 101 crash

November 15, 2015
MOUNTAIN VIEW : A San Jose man died when his Lexus sedan crashed into the median on Highway 101 north of the Highway 85 interchange, the California Highway Patrol reported.
Phiet Truong, 67, was identified Sunday by the Santa Clara County Coroner's office as the driver of the car. The cause of the crash was not immediately known.'
According to Officer Damian Cistaro, the CHP received a report at 10 p.m. Saturday of a solo-vehicle crash on Highway 101 north of the carpool lane flyover heading south on Highway 85. The four-door car appeared to have run into the median guardrail and also into a highway crash cushion, Cistaro reported. Arriving officers found the victim suffering major injuries.
Truong was transported to Stanford University Hospital, where he succumbed to his injuries.
The two left lanes of the freeway were closed for about an hour and a half.
An investigation into the cause of the crash is continuing.

By the way, Nov 2015 was when it was compacted, had no markings (no chevrons), and no pylons...

 

[SMAlset]

Wow, TEG so there is more to investigate so to speak. Glad you didn't hang it up. So same exact location, same cushion barrier, different car (Lexus) that time. Unfortunately same result for the driver. Back in 2015. Wonder how many more reports will turn up. Wonder what his car looked like.

 

[TEG]

Also:
Roadshow: Tailgaters create havoc in Highway 85 carpool lane – East Bay Times

...
Nov 2014:
I drive an electric car so I use the carpool lane on Highway 101 and Highway 85 southbound in the morning. I am going with or slightly faster than the flow of traffic in the next lane over and in the carpool lane (generally 65 to 70). I am often tailgated, not by others in electric vehicles or carpoolers but by solo drivers in regular cars that are not even supposed to be in the carpool lane.

They get very aggressive, swerving back to the regular lane and then almost hitting me as they swerve back in front of me. Any chance the CHP could be out there to ticket these dangerous solo drivers?...

 

[SMAlset]

I came back tonight after looking at some more photos and was thinking about the windshield lying on the ground. The X has that long black connector that goes down to the front cameras and rear view mirror and you can make those out from the photos. Got me to wondering if the driver had a dashcam behind the rear view mirror next to the glass that might hold a SD card in it. Gosh would that be helpful to this investigation. The window popped out early in the collision (looks like the rear view mirror side of the windshield was laying face up from what I can tell) so no fire damage.

Since we've barely heard any eyewitness accounts, do you think the witnesses that the police spoke to that day were requested to not speak about it publicly until the investigation is complete? Never been a witness to such an accident but I have been surprised how few individual reports we've heard.

I'm still having trouble figuring out where the white car impacted the Tesla that resulted in the damage it had.

 

[f-stop]

Strange indeed.
As an engineer do you think it’s plausible that the car did a front somersault (as reported) over the leading edge of the battery (the low down but foremost really strong point).

regarding the car doing a somersault, as I believe was reported early on...

In one of the early videos from a helicopter flyover of the scene, I noticed the MX's large windshield seemed to be lying basically intact on the road, just behind the right rear wheel of the Audi involved in the incident. From that video and later photos I saw of it again (e.g. @TEG's post #333 and 334 of this thread) it appears that the front (ie wider, clear part) of the windshield is facing north, or against the direction of traffic. I've been wondering how did it get there?

Now if you look closer at the 2nd photo in post #333, photo reproduced below, I think you can see the rear view mirror assembly still attached to the windshield on the inside of the glass facing UP. So to me, it looks like the intact windshield is on the ground upside down and facing against the direction of traffic. Could that be a clue that the windshield maybe popped off after the car's front was sheared off and the rest was halfway through a front somersault just after impacting the barrier??

I guess there's a number of different paths the windshield could have taken to arrive there but it just got me thinking when I noticed that rear view mirror...



edit: aha, I just noticed SMAlset and I posted something about the windshield almost simultaneously

 

[SMAlset]

Great minds f-stop!

This image is from NBCBayArea's anonymous witness' video. That large part on 85 has to be part of the hood, no? The steering wheel BTW with deployed airbag was on the car side of the wall south of it but near the wall. They had it circled in marker spray paint--from KTVU's noon hour broadcast.

Driver Dies Following Fiery Tesla Model X Crash on Hwy. 101

 

[arnolddeleon]

That sounds like people are being guided to play "chicken" where they go onto the 85 offramp for a while to go faster than the carpool on the right, then cut across the gore area at the last minute to get into the correct carpool lane. If someone tried to cut it close and hit the smart cushion rails it could drag them into the wall. This had been speculated before, but the suggestion that the left carpool flows better than the right gives new reason why people might be doing that more. And again we are back to the thought that there should be candelstick delineators (plastic poles) in the gore area to discourage people from doing that.

The caveat I would add is it is not necessarily faster to be in left most lane, for my drive today the #2 carpool lane was practically empty, so a more aggressive driver could go around on the right carpool lane and pass a lot of cars on the left and right. I am speculating that there enough drivers that prefer to be away from slower traffic so they go for the left lane.

 

[mattack4000]

You have probably never traveled on this spot, I timed it and the gore point has enough space for you to travel for 5 full seconds before contact with the wall at 75mph. 5+ seconds! The line condition is not great, but no where close to be bad either.


[QUOTE="cbdream99, post: 2643117, member
If the car already entered the gore area for whatever reasons, then it is possible the car will keep on going until the driver realized that's not a lane and naturally make emergency maneuver.. It's 930am in the morning, I am not sure how bad is the sun's glare or whether it is a contributing factor to the system, but human is easy to miss if the car is already inside the gore area.

I hope Tesla will fully cooperate with the authority and disclose all data they have, and eye witnesses will come out and provide any information.[/QUOTE]

 

[Haddock]

Here's a picture from back in 2014.

 

[Swampgator]

I just noticed this:
Mountain View: Driver dies in Hwy. 101 crash – East Bay Times


By the way, Nov 2015 was when it was compacted, had no markings (no chevrons), and no pylons...
View attachment 289855
View attachment 289856

Still looked that way in October 2015.

 

[SMAlset]

So if the highway speed impact compresses the front end so much that it catches the bumper, splays open the front body section as it pushes forward, it looses it's left wheel/tire/suspension at the barrier and the momentum flips the car end-over-end (Rear goes over first) how does the hood end up on 85 and down a ways and the windshield ends up on 101 nearer the barrier and with the car in between both parts. I would think they would come off close together in time and land at least in the same direction.

The hood of the white car, looks creased on the left side and pushed in towards the middle of the hood. The driver door is mangled quite a bit and the front driver side section is gone. Could the Tesla have somehow struck the white car when it hit the ground and slid or something like that? Or does it look more like the white car struck the Tesla as it tried to navigate past it? I'm thinking the former from the clues in how things got bent on the white car. Didn't see white paint on the blue car and while I don't really notice any blue paint on the white car am guessing that there would be some on the parts that came off the white car's driver's front.

Does any of this make sense?

 

[Swampgator]

So if the highway speed impact compresses the front end so much that it catches the bumper, splays open the front body section as it pushes forward, it looses it's left wheel/tire/suspension at the barrier and the momentum flips the car end-over-end (Rear goes over first) how does the hood end up on 85 and down a ways and the windshield ends up on 101 nearer the barrier and with the car in between both parts. I would think they would come off close together in time and land at least in the same direction.

The hood of the white car, looks creased on the left side and pushed in towards the middle of the hood. The driver door is mangled quite a bit and the front driver side section is gone. Could the Tesla have somehow struck the white car when it hit the ground and slid or something like that? Or does it look more like the white car struck the Tesla as it tried to navigate past it? I'm thinking the former from the clues in how things got bent on the white car. Didn't see white paint on the blue car and while I don't really notice any blue paint on the white car am guessing that there would be some on the parts that came off the white car's driver's front.

Does any of this make sense?

One thing is clear no matter the outcome of this investigation......Automatic emergency braking does not work for stationary objects like walls and concrete barriers. Why can;t Tesla get this part right?

 

[Haddock]

This is pretty poor signage. For comparison, here's what something like that looks like in the UK.

Note the clear road markings. This is Spaghetti Junction in the UK and the two left lanes are exiting. They are separated by road markings so people don't change between the two exiting lanes.

Here is Holland. Nice big vertical green chevron sign to alert you:

Also a patch of grass which doesn't look like an extra lane. Here's Sweden, the champions of safety:

Again, nice big chevron sign, and rumble strips to warn you that you are not supposed to cross the lines.

Really, once you have to remove the sand bags because people crash into them too often perhaps it's time to rethink the signage. I won't even mention having an exit lane on the left of the highway instead of the right, because that happens all the time in the US and just seems crazy to Europeans. The huge trucks are supposed to cut across 7 lanes to exit? OK I mentioned it.

 

[NeverFollow]

This picture showing a driver getting confused and driving in the lane is very helpful,
especially if you imagine a truck in front of the model x or something.
View attachment 289798

The carpool painting is not consistent.

In some areas, the carpool is clearly indicated using 4 yellow separation stripes.

I have myself been caught been in the carpool lane, especially when following a big SUV or a small delivery truck,
because suddenly the left lane becomes a carpool lane, the diamond sign might have faded and the small side signs
are not in the line of site when following a tall vehicule, and then it's very difficult and dangerous to move to the right lane.


Dumbarton Bridge, Fremont, CA - Carpool lane separated with 4 yellow stripes

 

[mongo]

There are 2 HOV lanes at the gore point, not one. The left hand HOV lane starts as a fork where the southbound Bayshore Freeway widens out about 3.5 miles north of Freeway 85. Again, following the simplest scenario, the Model X was on Autopilot, and in the HOV lane 4 miles north. When the HOV lane(s) doubled 3.5 miles north, the Model X, stayed in the lane it was in, which at that point became the #2 lane (and still an HOV marked lane). It stayed in the #2 lane until the gore point, where because of a bad sun angle, and worn lane markings at the gore point, it followed the wrong solid white line, into the barrier. The assumptions behind this scenario require no mistakes by the driver (other than inattentiveness), or other drivers, only unfavorable conditions for resolving lane control by AP, which we know was true.

Counterpoint: That scenario does not align with the CHP report that mentioned "driver lost control", unless they only meant that in the sense that no one drives into a barrier on purpose. A straight in impact also seems like it would create a different debris pattern.

One thing is clear no matter the outcome of this investigation......Automatic emergency braking does not work for stationary objects like walls and concrete barriers. Why can;t Tesla get this part right?

That is not clear from this incident because we do not know the approach path of the car, or the driver inputs. AEB is designed to reduce rear end collision speed due to slowing vehicles, not preventing hitting stationary objects.
Part of the issue being radar cannot tell if you are heading toward a stationary object or moving cross traffic that will clear. Systems with other sensors such as lidar or vision do have the data to detected stopped objects, and Tesla is working on using that.
From the S 6.2 release notes (expect X to be similar):

Automatic Emergency Braking
Automatic Emergency Braking — a new Collision Avoidance Assist feature — is designed to automatically engage the brakes to reduce the impact of an unavoidable frontal collision.
Automatic Emergency Braking will stop applying the brakes when you press the accelerator pedal, press the brake pedal, or sharply turn the steering wheel.
Automatic Emergency Braking is enabled by default. You can temporarily disable this feature via the AUTOMATIC EMERGENCY BRAKING setting in Controls > Settings > Driver Assistance > COLLISION AVOIDANCE ASSIST. Automatic Emergency Braking will re-enable when you next drive.
Note: Automatic Emergency Braking operates when you are driving at speeds between 5 mph (8 km/h) and 85 mph (140 km/h).

Over 85 (on this release) no AEB
Pushing accelerator no AEB
Turning wheel 'sharply' no AEB

 

[mongo]

Might be plausible that he was just going straight in the gore area (mistakenly thinking it was the lane), and hit the barrier (which is offset to the left) causing it to rotate to the right, then the Mazda hit it and pushed it toward the wall, and then the Audi hit it and pushed it even more into the wall.

View attachment 289814

I hear what you are saying. My issue with that is the middle impact point seems so centered that the lack of a left to right sideways moment would cause the vehicle to end over end instead of spin to the right. If it did a full nose down tip, the roof/ windshield seem like they would be damaged and that there would be scrap marks on the barrier.