FYI: Many of us know this but many others may not. If your v is involved in an accident most auto insurance companies today will hook into your OBD II unit to download your last 15 seconds or less "driving history" which will also show braking. If your story and the OBD II history do not say the same thing you may be in for problems even including a BIG raise in rates or cancellation. Ex. - If you say you braked and it is not shown in the history you are going to have "problems" with your insurance company.
I have never seen or heard of that happening, not that it might provide the data you suggest. Is there a triggering condition (total, injury, fatality) that causes an intent to download?
Yes, most modern vehicles "store" the last 15 to 30 seconds of data, which can be accessed by law enforcement or insurance companies. Data includes speed, braking, throttle position, etc. SCH-I535
Have you ever heard of this being accessed? Under what conditions, data preservation procedures, custody, etc.?
This data storage first appears on Corvettes around 2005 and has since expanded to most vehicles. It protects auto companies from fraudulent complaints and insurance companies and law enforcement with facts that are accepted in court. And yes, all the above mentioned entities have used this data. You can also use it to uphold your (true) account of events just prior to a crash.
It is commonly used. I've read that there is actually some legislation being considered to stop the practice on a invasion of privacy perspective. The feeling is that you own the car and therefore the data. Makes sense to me. They should not be able to take the data w/o at least a court order.
also g-force and with electric steering, steering angle. The cops here in the UK have only just started downloading and using this data. As a side note, analogue speedometers are designed to break upon impact, the needle sticks at the indicated speed on collision and they can read the impact speed from that. This and skid marks were the data they used until recently.
Doesn't seem to be SOP here. Perhaps only in injury/fatality accidents, about which we thankfully have no experience.
