# Presentation: 892053

##  EDR User Perspectives on Parameters & Data Accessibility: Independent Investigator/ConsultantAccident Reconstruction

- Robert C. McElroy, Ph.D.
- Forensic Accident Investigations, Inc.

- <date/time>

***SAE***

## A Personal Introduction

- 30+ years automotive industry
- Former GM technical executive
- NHTSA EDR groups participation
- SAE & IEEE EDR Committees **( 3 )**
- Consulting – EDR, vehicle technology, & accident reconstruction
- Ph.D. – Texas A&M

**PPV **
**T&B**

**Industrial Engineering **
**Statistics**

## Accident Reconstruction

- Traffic Traffic Accident Reconstruction is the effort to determine, from whatever information is available, *how* the accident occurred.
- Reconstruction is not determining *why* an accident happened.

## Examples

- “Ouch”

- Impact

- Example #1:
-   out & down

- Example #2:
-   impact &
-   final rest

- Final Rest

- Crash analysis can be
- simple or complex,
- with or without EDR.

## Slide 5

## Slide 6

## Accident Reconstruction

- Traffic Traffic Accident Reconstruction is the effort to determine, from whatever information is available, *how* the accident occurred.
- Reconstruction is not determining *why* an accident happened.

## EDR User Perspective Issues

- Data ownership
- Vehicles with downloadable data
- Data retrieval
- Data interpretation
- Correlation of data sources
- Report findings
- Frye hearings

## Data Ownership ( simplified )

**Owner / Driver of the vehicle owns the data**
**Insurance company rights to the data**
**Manufacturer proprietary data**

## Does Vehicle Have Data ?

**Age / Model**
**Manufacturer**
**Type of impact**

## Direct connection to EDR
OBD connector under the dash

**OBD connector under the dash**

- Data Retrieval

## Data Interpretation

**Type of crash**
**Front / Side / Rear / Pedestrian / etc.**
**Pre crash events**
**Delta V**
**Vehicle integrity**
** ****Electrical / Physical**

## Correlation of Data Sources

**EDR data**
**Vehicle damage data**
**Site data**
**Pre impact data**
**Impact data**
**Post impact data**

## Technology Challenges

- LED and HID lamps do not have visible post impact damage profiles like “hot shock”.
- Drive by wire, steer by wire, brake by wire systems eliminate traditional technology which can be examined after a crash.

## Report Findings

- Are analysis and results consistent  ? ? ?
-  ABS Skid Marks
-  Electronic Controls
-  Non-Filament Lamps
-  Vehicle Damage

## Frye Hearing

**Data admissibility in court.**
**Does this technology have validity which permits it to be accepted as evidence.**
**NHTSA EDR Working Groups.**
**History and development of EDR.**

## Traffic Accident ReconstructionPractical Examination

- 2 Test Examples

## Real World Example # 1EDR or Conventional Analysis ?

- But I was pushing
- on the brake

## Real World Example # 2

- 1

- 2

- 3

- 4

- Basic Analysis
- Truck Energy (1) =
- Car Energy (2+3+4)

## Real World Example # 2Vehicle 1 = Vehicles 2+3+4

- Real World Example # 2Vehicle 1 = Vehicles 2+3+4

- 1

- 2

- 3

- 4

## EDR Needs

- Standardized light vehicle data set
- Standardized heavy vehicle data set
- Common connector system
- Common retrieval method
- EDR “Policy”

## EDR “Policy” Foundation

- NTSB identifies need for EDR
- NTSB Symposiums, #1, #2, & #3
- NHTSA working groups, PPV + T&B
- NHTSA EDR Petition Review
- SAE & IEEE Committees

## EDR Policy Solution

- Standardize data set

## EDR Policy Benefits To Society

*Save lives,*
*Increase public confidence in transportation system,*
*Provides inherent accountability for collision vehicles, and*
*Reduces, to some extent, the complexity of collision analysis.*

## Questions & Comments