Speedometer Reading After Crash
 

Over the weekend, I had a conversation with some friends on a recent
accident involving NJ governor. It was reported by news media that the
SUV was going at 91 MPH prior to the crash. My question was how they
found out the speed, and one answer was that a speedometer would stuck
at the speed the moment of the impact. I find it very hard to believe
that any speedometer would stuck at the correct reading considering
the violent nature of the collisions, unless the speedometers are very
specially designed to record speeds and to sense the crash. Can anyone
shed some lights on how accident investigators figure out the crash
speeds?

Speedometer Reading After Crash
 

panabiker > wrote in news:1177600190.710477.26660
@u32g2000prd.googlegroups.com:

> Over the weekend, I had a conversation with some friends on a recent
> accident involving NJ governor. It was reported by news media that the
> SUV was going at 91 MPH prior to the crash. My question was how they
> found out the speed, and one answer was that a speedometer would stuck
> at the speed the moment of the impact. I find it very hard to believe
> that any speedometer would stuck at the correct reading considering
> the violent nature of the collisions, unless the speedometers are very
> specially designed to record speeds and to sense the crash. Can anyone
> shed some lights on how accident investigators figure out the crash
> speeds?
>
>

the black box will record the last 5 seconds of info on newer vehicles.
KB

--
Thunder Snake #9
"Protect" your rights or "lose" them.

Speedometer Reading After Crash
 

panabiker wrote:
> Over the weekend, I had a conversation with some friends on a recent
> accident involving NJ governor. It was reported by news media that the
> SUV was going at 91 MPH prior to the crash. My question was how they
> found out the speed, and one answer was that a speedometer would stuck
> at the speed the moment of the impact. I find it very hard to believe
> that any speedometer would stuck at the correct reading considering
> the violent nature of the collisions, unless the speedometers are very
> specially designed to record speeds and to sense the crash. Can anyone
> shed some lights on how accident investigators figure out the crash
> speeds?
>
onboard black box.
confession.
measuring skid marks.
recreating the accident scene - how far did the vehicle slide, etc...

but, probably just an educated guess.

Ray

Speedometer Reading After Crash
 

On Apr 26, 11:09 am, panabiker > wrote:
> Over the weekend, I had a conversation with some friends on a recent
> accident involving NJ governor. It was reported by news media that the
> SUV was going at 91 MPH prior to the crash. My question was how they
> found out the speed, and one answer was that a speedometer would stuck
> at the speed the moment of the impact. I find it very hard to believe
> that any speedometer would stuck at the correct reading considering
> the violent nature of the collisions, unless the speedometers are very
> specially designed to record speeds and to sense the crash. Can anyone
> shed some lights on how accident investigators figure out the crash
> speeds?

Probably read it off the "black box" instead of looking at the
speedometer.

nate

Speedometer Reading After Crash
 

it was likely the black box.
in the old school, they would formula it out.
weight of vehicle, length of skid marks, impact damage, etc.
although
unless there's a full on proper investigation, they're wrong.
my girlfriend was in a crash once, the cops said they hit that fence at
80 MPH.
hmmmmm...
1982 K10 @ 80mph + fence
seems like they should have done more than just knock the fence over
from 80 miles per hour. i don't care what anyone says, 80 is fast,
technically speaking, and that truck is very heavy. also considering
that not wearing a seatbelt in a 30mph crash has been known to cause
death. oh and plus no one was wearing seatbelts.
so sometimes they just throw numbers around, i think they think they're
cooler when they do that ****.


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Speedometer Reading After Crash
 

panabiker wrote:
> Over the weekend, I had a conversation with some friends on a recent
> accident involving NJ governor. It was reported by news media that the
> SUV was going at 91 MPH prior to the crash. My question was how they
> found out the speed, and one answer was that a speedometer would stuck
> at the speed the moment of the impact. I find it very hard to believe
> that any speedometer would stuck at the correct reading considering
> the violent nature of the collisions, unless the speedometers are very
> specially designed to record speeds and to sense the crash. Can anyone
> shed some lights on how accident investigators figure out the crash
> speeds?
>

Easy to do IF you have access to the proper software. They just plug
into the OBD port and query the airbag module for the vehicle parameters
at the time it deployed. It saves the information just like the freeze
frame data that gets stored when the MIL comes on. It will tell them the
speed, throttle position, engine RPMs, in what order the sensors for the
bag(s)tripped,if you had the brakes applied (also shows if ABS was
functioning at the time), seat belt use, exterior temperature. Plus a
few other items.


--
Steve W.

Speedometer Reading After Crash
 

No belt and 90 mph, I'd like to get a ticket for either in Jersey and
have my say in court. Tricky as to what agencys have access to the
SIRS module info after a deployment. Good info., lugnut.


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Speedometer Reading After Crash
 

> No belt and 90 mph, I'd like to get a ticket for either in Jersey and
> have my say in court. Tricky as to what agencies have access to the
> SIRS module info after a deployment.

Hopefully as a mere matter of getting a ticket -- actually stuff the
car at 90 with no belt, "you should have such problems."

To get back to the original poster's question: I doubt that they
would find a speedo stuck at 90 (in the car, that is; if your
Speedo gets stuck at 90; well, you and all your buddies at the
senior center should have such problems). Needles getting frozen at
some reading is an ancient theme from fictional and apparently some
factual accounts of aircraft crashes, violent disruptions of one's
person in the era of mechanical wrist watches, etc. I am thinking
that that takes extreme g's, especially in the case of an instrument
where the position of the needle is a dynamic rather than a static
affair (stopping a mechanical clock might be a lot easier to arrange,
John Cameron Swayze notwithstanding).

A quick glance through the literature of a field not my own indicates
that a slap mark on the *face* of a speedometer is what investigators
are usually looking for after a motor vehicle crash, not the needle's
actually being frozen. Mythbusters could doubtless have a lot of
fun with some old jalopies and an abandoned runway in this regard.

As others have pointed out, there are several other ways of
determining the crash speed through forensics at the general crime
scene, perhaps onboard computers, and occupants coming clean about the
situation.

Cheers,
--Joe

Speedometer Reading After Crash
 

keep in mind - it was a state police owned and operated vehicle, and the
occupant was the governor of the state - I would assume that both the
vehicle and the governor are tracked by GPS most of the time.




Ad absurdum per aspera wrote:
>> No belt and 90 mph, I'd like to get a ticket for either in Jersey and
>> have my say in court. Tricky as to what agencies have access to the
>> SIRS module info after a deployment.
>
> Hopefully as a mere matter of getting a ticket -- actually stuff the
> car at 90 with no belt, "you should have such problems."
>
> To get back to the original poster's question: I doubt that they
> would find a speedo stuck at 90 (in the car, that is; if your
> Speedo gets stuck at 90; well, you and all your buddies at the
> senior center should have such problems). Needles getting frozen at
> some reading is an ancient theme from fictional and apparently some
> factual accounts of aircraft crashes, violent disruptions of one's
> person in the era of mechanical wrist watches, etc. I am thinking
> that that takes extreme g's, especially in the case of an instrument
> where the position of the needle is a dynamic rather than a static
> affair (stopping a mechanical clock might be a lot easier to arrange,
> John Cameron Swayze notwithstanding).
>
> A quick glance through the literature of a field not my own indicates
> that a slap mark on the *face* of a speedometer is what investigators
> are usually looking for after a motor vehicle crash, not the needle's
> actually being frozen. Mythbusters could doubtless have a lot of
> fun with some old jalopies and an abandoned runway in this regard.
>
> As others have pointed out, there are several other ways of
> determining the crash speed through forensics at the general crime
> scene, perhaps onboard computers, and occupants coming clean about the
> situation.
>
> Cheers,
> --Joe
>

Speedometer Reading After Crash
 

Software is not necedssarily needed, speedometer needles have stuck at speed
in accidents many years before onboard computers were installed on cars.
Roy
"Steve W." > wrote in message ...
> panabiker wrote:
>> Over the weekend, I had a conversation with some friends on a recent
>> accident involving NJ governor. It was reported by news media that the
>> SUV was going at 91 MPH prior to the crash. My question was how they
>> found out the speed, and one answer was that a speedometer would stuck
>> at the speed the moment of the impact. I find it very hard to believe
>> that any speedometer would stuck at the correct reading considering
>> the violent nature of the collisions, unless the speedometers are very
>> specially designed to record speeds and to sense the crash. Can anyone
>> shed some lights on how accident investigators figure out the crash
>> speeds?
>>
>
> Easy to do IF you have access to the proper software. They just plug into
> the OBD port and query the airbag module for the vehicle parameters at the
> time it deployed. It saves the information just like the freeze frame data
> that gets stored when the MIL comes on. It will tell them the speed,
> throttle position, engine RPMs, in what order the sensors for the
> bag(s)tripped,if you had the brakes applied (also shows if ABS was
> functioning at the time), seat belt use, exterior temperature. Plus a few
> other items.
>
>
> --
> Steve W.
>