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There’s excellent discussion about the accident at the Tesla forum. [1] The big take-away from their research is that particular exit-only left-lane (which is

by zaroth 9y ago

There’s excellent discussion about the accident at the Tesla forum. [1] The big take-away from their research is that particular exit-only left-lane (which is one of two side by side carpool lanes) is poorly marked, has been consistently gotten worse as changes have been made to the road over the last several years, does not have proper lane markings (missing chevrons in the non-lane), routinely has cars cutting right across the gore point (to the point where there are dash cam videos of almost accidents at that exact point linked in the forum) and, most damning of all, the resettable safety cushion device [2] which protects the gore point had already been hit just recently and there’s evidence it had not been reset when it was hit again by the Model X, which meant the X suffered a direct impact with a narrow slice of concrete. If anything I think NTSB should be investigating Caltrans for this one. [1] - https://teslamotorsclub.com/tmc/threads/model-x-crash-on-us-101-mountain-view-ca.111505/ https://teslamotorsclub.com/tmc/threads/model-x-crash-on-us-... [2] - https://teslamotorsclub.com/tmc/posts/2636752/ https://teslamotorsclub.com/tmc/posts/2636752/

cdibona 9y ago
I commute on this part of the road every single day, and every day there are people whipping and and out of the two hov lanes as they approach the flyway fork. The model X was probably trying to make it into the flyway at the last minute or continue down the 101 part at the last moment, cut across thinking they had time, and fatally misjudged. NTSB should look into this in the event that the person was under autopilot at the time, or if there was some flaw in the design of the model X that should have helped or mitigated the death of the driver. I would love to see better guidelines for tesla and for emt/fire staff as the road was shut down for about 6 hours while they tried to deal with the battery. Someone from tesla eventually came down and helped the fire dept deal with the fire... So, sure, this is a tricky and maybe even dangerous fork, and caltrans will probably put in those dividers like the ones on southbound old middlefield road, but its okay and smart to look into the driver, the model x and the subsequent 6 hours of delay and blockage to improve safety across the board.
- grzm 9y ago
  > "NTSB should look into this in the event that the person was under autopilot at the time, or if there was some flaw in the design of the model X that should have helped or mitigated the death of the driver. I would love to see better guidelines for tesla and for emt/fire staff as the road was shut down for about 6 hours while they tried to deal with the battery. Someone from tesla eventually came down and helped the fire dept deal with the fire..." This is explicitly what the NTSB mentioned in their tweet (included in the article) announcing the investigation: > "2 NTSB investigators conducting Field Investigation for fatal March 23, 2018, crash of a Tesla near Mountain View, CA. Unclear if automated control system was active at time of crash. Issues examined include: post-crash fire, steps to make vehicle safe for removal from scene." https://twitter.com/NTSB_Newsroom/status/978651644417265664 https://twitter.com/NTSB_Newsroom/status/978651644417265664
userbinator 9y ago
Interesting. I've not seen those before, but I wonder why they weren't able to make it automatically reset itself (providing it hadn't been damaged enough to prevent that).
- bagels 9y ago
  They are destructively consumed in a crash, just as a car's crumple zones are.
  - zaroth 9y ago
    The whole point is it can be reset in ~45 minutes with $40 of parts. There are some bolts which shear off but a typical collision will not actually destroy it! Informational sheet describing the benefits: http://www.dot.ca.gov/hq/esc/oe/project_ads_addenda/06/06-0Q3504/supplemental_info/06-0Q3504IH.pdf http://www.dot.ca.gov/hq/esc/oe/project_ads_addenda/06/06-0Q...
    - bagels 9y ago
      That's pretty great. Its still destructive (just less destructive than I expected), and not automatically reset.
mirimir 9y ago
Ah, I was wondering how there could be so much velocity relative to a "lane divider".
debt 9y ago
I think what's being massively overlooked in many crashes that involved Tesla is the insane inferno caused by the impact on the batteries. I mean, the guy died from the burns from the inferno, not from the actual impact of the crash. The picture shows the front side of the car completely incinerated. Not to mention, the cleanup of the crash took much longer than it should've because of the EMS had serious concerns about the melted batteries. Tesla cars are great until you get trapped inside a battery-fueled inferno. Youtube it, those batteries literally create a meteoric fireball.
- space_fountain 9y ago
  I'm by no means sure of the relative danger, but plain old gas cars can also have pretty big fires. Is it actually worse with batteries? The energy density is if anything lower.
  - sjwright 9y ago
    At least with liquid fuels, the job of a fireman can be as simple as extinguishing the existing flame and cooling down anything that is hot. It's not so simple to stop a damaged lithium battery from continuously self-igniting. Read about the recent incident with the Rimac Concept One—it kept catching fire for five days!
    - JshWright 9y ago
      > At least with liquid fuels, the job of a fireman can be as simple as extinguishing the existing flame and cooling down anything that is hot. As a firefighter, I think you and I likely have different ideas of what "simple" looks like in this case... EVs definitely pose unique hazards, but there is nothing "simple" about a car fire.
      - sjwright 9y ago
        That is fair. But I suspect your training and experience with car fires is substantial compared to EV fires. I suppose I didn't meant to say they are simple but rather well understood. I wonder when there are literally hundreds of unique popular models of EV on the road, whether there will be issues arising from having innumerable unique designs for battery packs, first responder lines etc.
stevenwoo 9y ago
There was someone on page 6/31 who said the barrier was there at 5:30 pm on the previous day. That theory is over if he is correct. edit: correction this photo evidence from the day before shows the barrier not replaced. https://finance.yahoo.com/news/tesla-knows-fatal-model-x-030154661.html?hl=1&noRedirect=1 https://finance.yahoo.com/news/tesla-knows-fatal-model-x-030...
hangonhn 9y ago
"the X suffered a direct impact with a narrow slice of concrete." Does anyone know if that sort of impact would be what the IIHS calls small overlap frontal crash? IIRC when they added that test in 2012, many previously very safe cars were found to do poorly in that specific test because so much energy is concentrated into a very small area.
- hkmurakami 9y ago
  I was watching videos of that test and I actually laughed as a Volvo s60 abruptly careened off to the right as the overlap object hit a deflection bar/panel in the engine compartment, thereby protecting the passenger area. Living up to its reputation as very safe vehicle.
  - sorahn 9y ago
    Got a link?
    - y4mi 9y ago
      probably this one https://www.youtube.com/watch?v=YSYLE55iYj0 https://www.youtube.com/watch?v=YSYLE55iYj0 or the more recent: https://www.youtube.com/watch?v=nnRIwQn9SA8 https://www.youtube.com/watch?v=nnRIwQn9SA8 the latter is imo even more amazing
      - hkmurakami 9y ago
        Yup it was something very very similar to these, by the same organization.
      - erk__ 9y ago
        There is also one with an Tesla, and I think that it looks worse than any of the two Volvos. https://www.youtube.com/watch?v=fMcuiFmIQTo https://www.youtube.com/watch?v=fMcuiFmIQTo
    - hkmurakami 9y ago
KKKKkkkk1 9y ago
Who needs NTSB when we have the Tesla Motors Club.
fishywang 9y ago
Caltrans? Really? I'm not referring to this particular case, but similar cases in general: There are a lot of people merging right on that place in the last minute, just like there are a lot of people merge left on an exit only lane on any other highway exits. It's not because they are poorly marked, it's because the exit only lane moves faster and they want to cut other people. Even if the lanes are poorly marked (I don't think the side-by-side carpool lanes are poorly marked, there are plenty of signs indicates that the left one is exit only) and they are on the exit only lane by accident, they should still have a common sense about what's safe to do. They can always exit there and come back to the highway on the next entrance. They just decided that their time is too valuable to do that so they are just jerking around. How is that Caltrans' fault?
stefan_ 9y ago
No, you can not drive into a wall, even if that wall has been missing it's safety cushion to protect those stupid enough to drive into a wall.

by zaroth 9y ago

cdibona 9y ago

I commute on this part of the road every single day, and every day there are people whipping and and out of the two hov lanes as they approach the flyway fork. The model X was probably trying to make it into the flyway at the last minute or continue down the 101 part at the last moment, cut across thinking they had time, and fatally misjudged. NTSB should look into this in the event that the person was under autopilot at the time, or if there was some flaw in the design of the model X that should have helped or mitigated the death of the driver. I would love to see better guidelines for tesla and for emt/fire staff as the road was shut down for about 6 hours while they tried to deal with the battery. Someone from tesla eventually came down and helped the fire dept deal with the fire... So, sure, this is a tricky and maybe even dangerous fork, and caltrans will probably put in those dividers like the ones on southbound old middlefield road, but its okay and smart to look into the driver, the model x and the subsequent 6 hours of delay and blockage to improve safety across the board.

grzm 9y ago
> "NTSB should look into this in the event that the person was under autopilot at the time, or if there was some flaw in the design of the model X that should have helped or mitigated the death of the driver. I would love to see better guidelines for tesla and for emt/fire staff as the road was shut down for about 6 hours while they tried to deal with the battery. Someone from tesla eventually came down and helped the fire dept deal with the fire..." This is explicitly what the NTSB mentioned in their tweet (included in the article) announcing the investigation: > "2 NTSB investigators conducting Field Investigation for fatal March 23, 2018, crash of a Tesla near Mountain View, CA. Unclear if automated control system was active at time of crash. Issues examined include: post-crash fire, steps to make vehicle safe for removal from scene." https://twitter.com/NTSB_Newsroom/status/978651644417265664 https://twitter.com/NTSB_Newsroom/status/978651644417265664

userbinator 9y ago

Interesting. I've not seen those before, but I wonder why they weren't able to make it automatically reset itself (providing it hadn't been damaged enough to prevent that).

bagels 9y ago
They are destructively consumed in a crash, just as a car's crumple zones are.
- zaroth 9y ago
  The whole point is it can be reset in ~45 minutes with $40 of parts. There are some bolts which shear off but a typical collision will not actually destroy it! Informational sheet describing the benefits: http://www.dot.ca.gov/hq/esc/oe/project_ads_addenda/06/06-0Q3504/supplemental_info/06-0Q3504IH.pdf http://www.dot.ca.gov/hq/esc/oe/project_ads_addenda/06/06-0Q...
  - bagels 9y ago
    That's pretty great. Its still destructive (just less destructive than I expected), and not automatically reset.

mirimir 9y ago

Ah, I was wondering how there could be so much velocity relative to a "lane divider".

debt 9y ago

I think what's being massively overlooked in many crashes that involved Tesla is the insane inferno caused by the impact on the batteries. I mean, the guy died from the burns from the inferno, not from the actual impact of the crash. The picture shows the front side of the car completely incinerated. Not to mention, the cleanup of the crash took much longer than it should've because of the EMS had serious concerns about the melted batteries. Tesla cars are great until you get trapped inside a battery-fueled inferno. Youtube it, those batteries literally create a meteoric fireball.

space_fountain 9y ago
I'm by no means sure of the relative danger, but plain old gas cars can also have pretty big fires. Is it actually worse with batteries? The energy density is if anything lower.
- sjwright 9y ago
  At least with liquid fuels, the job of a fireman can be as simple as extinguishing the existing flame and cooling down anything that is hot. It's not so simple to stop a damaged lithium battery from continuously self-igniting. Read about the recent incident with the Rimac Concept One—it kept catching fire for five days!
  - JshWright 9y ago
    > At least with liquid fuels, the job of a fireman can be as simple as extinguishing the existing flame and cooling down anything that is hot. As a firefighter, I think you and I likely have different ideas of what "simple" looks like in this case... EVs definitely pose unique hazards, but there is nothing "simple" about a car fire.
    - sjwright 9y ago
      That is fair. But I suspect your training and experience with car fires is substantial compared to EV fires. I suppose I didn't meant to say they are simple but rather well understood. I wonder when there are literally hundreds of unique popular models of EV on the road, whether there will be issues arising from having innumerable unique designs for battery packs, first responder lines etc.

stevenwoo 9y ago

There was someone on page 6/31 who said the barrier was there at 5:30 pm on the previous day. That theory is over if he is correct. edit: correction this photo evidence from the day before shows the barrier not replaced. https://finance.yahoo.com/news/tesla-knows-fatal-model-x-030154661.html?hl=1&noRedirect=1 https://finance.yahoo.com/news/tesla-knows-fatal-model-x-030...

hangonhn 9y ago

"the X suffered a direct impact with a narrow slice of concrete." Does anyone know if that sort of impact would be what the IIHS calls small overlap frontal crash? IIRC when they added that test in 2012, many previously very safe cars were found to do poorly in that specific test because so much energy is concentrated into a very small area.

hkmurakami 9y ago
I was watching videos of that test and I actually laughed as a Volvo s60 abruptly careened off to the right as the overlap object hit a deflection bar/panel in the engine compartment, thereby protecting the passenger area. Living up to its reputation as very safe vehicle.
- sorahn 9y ago
  Got a link?
  - y4mi 9y ago
    probably this one https://www.youtube.com/watch?v=YSYLE55iYj0 https://www.youtube.com/watch?v=YSYLE55iYj0 or the more recent: https://www.youtube.com/watch?v=nnRIwQn9SA8 https://www.youtube.com/watch?v=nnRIwQn9SA8 the latter is imo even more amazing
    - hkmurakami 9y ago
      Yup it was something very very similar to these, by the same organization.
    - erk__ 9y ago
      There is also one with an Tesla, and I think that it looks worse than any of the two Volvos. https://www.youtube.com/watch?v=fMcuiFmIQTo https://www.youtube.com/watch?v=fMcuiFmIQTo
  - hkmurakami 9y ago

KKKKkkkk1 9y ago

Who needs NTSB when we have the Tesla Motors Club.

fishywang 9y ago

Caltrans? Really? I'm not referring to this particular case, but similar cases in general: There are a lot of people merging right on that place in the last minute, just like there are a lot of people merge left on an exit only lane on any other highway exits. It's not because they are poorly marked, it's because the exit only lane moves faster and they want to cut other people. Even if the lanes are poorly marked (I don't think the side-by-side carpool lanes are poorly marked, there are plenty of signs indicates that the left one is exit only) and they are on the exit only lane by accident, they should still have a common sense about what's safe to do. They can always exit there and come back to the highway on the next entrance. They just decided that their time is too valuable to do that so they are just jerking around. How is that Caltrans' fault?

stefan_ 9y ago

No, you can not drive into a wall, even if that wall has been missing it's safety cushion to protect those stupid enough to drive into a wall.