Does EDR informasjon and physical evidence on the car need to match each other 100%?

This forum is for the open and public discussion of Accident Reconstruction topics. This is open to any registered user of the CrashForum.info site.
Post Reply
User avatar
exnetic
Posts: 2
Joined: Wed Feb 24, 2021 2:48 pm
First Name: Joachim
Last Name: Sjølander

Does EDR informasjon and physical evidence on the car need to match each other 100%?

Post by exnetic »

My reconstruksjon expert does not care about the physical evidence on the car but only say that the edr informasjon is 100% korrekt read out with bosch cdr tool.

from what i can see in the bosch cdr manual it says-

Airbag ECU data should be used in conjunction with other physical evidence obtained from the vehicle and the surrounding
circumstances.

That means that physical evidence and edr needs to match right?

Thanks.

User avatar
Rusty Haight
Posts: 624
Joined: Tue May 10, 2011 3:24 pm
First Name: W. R. Rusty
Last Name: Haight
Contact:

Re: Does EDR informasjon and physical evidence on the car need to match each other 100%?

Post by Rusty Haight »

Joachim: An "expert" who ignores the human, vehicle and environment information from a crash in favor of "just" the crash data alone isn't much of an expert.

The first thing you have to be able to do with a set of data is be able to answer the question: is this data from the crash I'm investigating? To that, you need to be able to say there are enough characteristics in the data to say it is from the crash and not something else. There will rarely be a "100% match" since the data is going to be more detailed than what we can usually see on the car or road; however, where you ignore the human, vehicle and environment, you're going to miss something that basically says "there's something unusual about the data here we need to consider" or "this data needs to be explained more thoroughly to be used effectively."
- Rusty Haight
Collision Safety Institute

User avatar
mchenrysoftware
Posts: 76
Joined: Mon Mar 05, 2012 7:49 pm
First Name: brian
Last Name: mchenry

Re: Does EDR informasjon and physical evidence on the car need to match each other 100%?

Post by mchenrysoftware »

Rusty i'm with you on that.
I'll add to what you said that the accuracy of EDR also depends on what year and model vehicle (so what EDR flavor) and what type of crash (um...was the EDR in the crush zone or moved etc involved?)
It's a piece of the crash reconstruction puzzle but never the full picture.
Here's a related question and response from last November:
Brian McHenry, McHenrySoftware.com
NEW!! LEASE pricing of msmac3D Software!! 3D Crash Reconstruction and Simulation Software.

User avatar
uwef_de
Posts: 62
Joined: Mon May 13, 2019 4:31 am
First Name: Uwe
Last Name: Fuerbeth
Location: Europe
Contact:

Re: Does EDR informasjon and physical evidence on the car need to match each other 100%?

Post by uwef_de »

I remember the appropriate quote from W. Vandiver:
“• The acquisition of EDR data replaces nothing in an investigation.....absolutely nothing.
• Any EDR data obtained should be considered ‚more‘ evidence, not ‚replacement‘ evidence.
• Sometimes extra information raises additional questions.....that's life!
• Depending on your definition, sometimes the [EDR] data may be ‚wrong‘.”

User avatar
exnetic
Posts: 2
Joined: Wed Feb 24, 2021 2:48 pm
First Name: Joachim
Last Name: Sjølander

Re: Does EDR informasjon and physical evidence on the car need to match each other 100%?

Post by exnetic »

Rusty Haight wrote: Thu Feb 25, 2021 10:14 am Joachim: An "expert" who ignores the human, vehicle and environment information from a crash in favor of "just" the crash data alone isn't much of an expert.

The first thing you have to be able to do with a set of data is be able to answer the question: is this data from the crash I'm investigating? To that, you need to be able to say there are enough characteristics in the data to say it is from the crash and not something else. There will rarely be a "100% match" since the data is going to be more detailed than what we can usually see on the car or road; however, where you ignore the human, vehicle and environment, you're going to miss something that basically says "there's something unusual about the data here we need to consider" or "this data needs to be explained more thoroughly to be used effectively."
Thank you for the answers, The car crash guy investigator has ignored more things from the bosch cdr manual.
It says vehicle speed is an average speed, And the investigator said the car had that speed at that specific time. and has ignored Speed, vehicle indicated data accuracy can be affected by various factors, such as significant changes in tire size. On the car it had aftermarked wheels 18, Stock size is 17.

But a question here, Is TRG 0 in EDR is that the time the airbag was deployed and the speed indicated, lets say 34 km/h 0 TRG airbag deployment and the car hit something with a speed of 34 km/h ?

Post Reply