ACCIDENT RECONSTRUCTION BASICS

PHIL BUCKLEY

JUNE 27, 2019

KCMBA

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CLE OBJECTIVE

1. Assure you know what to expect from an AR expert

– What is involved?

– How the work is done?

– What tools are important?

– What results can be expected?

– What formats will the results be available in?

– Effective Data presentation

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YOU SHOULD EXPECT…

• BASIC: Has prior formal reports/deposition experience/trial experience/recommendations

• Training in analytics & scientific support

• Prior related experience

• Quick understanding of “your incident” character

• A general investigation plan

• Clear visualization ability

• A Degree of Certainty in Opinion

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Degree of Certainty in Opinion

• Starting point ranges 0% to << 100% unlikely if I am involved – There is a contest for a reason!

• Most likely explanation can be <50%

• More likely than not (>50%)

• Reasonable degree of probability

• High degree of probability

• Reasonable certainty

• Reasonable degree of engineering certainty

• Absolutely certain – probably not going to happen

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DEFINITIONS ARE IMPORTANT

• ACCIDENT CAN INFER “ACT OF GOD” – INCIDENT HELPS FOCUS THE SITUATION IN A NEUTRAL

WAY ALLOWING FOR OTHER OUTCOMES – CRASH OR COLLISION ARE OFTEN USED FOR VEHICLE

• RECONSTRUCTION INFERS THAT WHICH IS KNOWN IS INCOMPLETE OR POTENTIALLY WRONG – FOR SOME REASON(S) THERE IS (A) DISAGREEMENT

ABOUT WHAT HAPPENED

• BASICS INFERS THIS CAN BECOME COMPLICATED – WHAT IS YOUR FIRST CLUE THIS ACCIDENT IS COMPLEX? – WHAT CAN YOU EXPECT FROM A RECONSTRUCTION? – WHEN SHOULD YOU LOOK FOR IT?

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Controversy

CRASH WRECK INCIDENT

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YOUR FIRST CLUE…

• Equivocal issue(s)

• Multiple conflicting stories or views of what happened – Story

• What they saw, felt, heard, smelled, tasted

– View • Where this person saw it from

– Missing data becomes very important • AR fills in the blanks, reconciles the “facts”

• Correlation is the goal

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YOUR QUESTIONS!

• You provide the legal basis of the potential claims

• Your expert provides the technical basis

– But , may not know the legalese…

– Finds a lot of things interesting…

• You formulate the questions that need to be answered to support those claims

– Your well formed questions will allow the AR expert to be efficient and economical in support of your case.

• Sooner is better!

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YOUR QUESTIONS!

• You are best served when your questions are focused on your legal case position

• You should tell the expert what your legal position – Is, or…

– what you think it is, or…

– that you need information to focus the position

• 1,2,3 priority – direct energy to greatest benefit

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Weak vs Strong cases

• Your strong case may not need an expert – No loose ends

– No jury bias potential

– Clear easy visualization of the incident

– Better yet, supportive, available documentation from a formal authority such as Highway Patrol, city police, OSHA

• But you may still benefit from Visualization – A picture is still worth a 1000 words

– A video can be worth a 1000 pictures

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What if the case is weak?

• Weakness comes from multiple sources; – Just plain bad case

– Apparent facts don’t clearly support the case

– Absentee facts in need to be uncovered

• Bad—get out with least damage

• Apparent facts need foundation work

• Absentee facts need to be dug out – local video/ unregistered witnesses/ scene changes caused

by the incident/ poor or non-produced photography/ Poor investigation report/ Bias statements by officials/ vehicle recalls/ unknown unknowns/

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JPB

View from NORTH View from SOUTH

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What if the case is weak?

• YOU REALLY WANT TO KNOW THIS!

–No case whatsoever!

–Weak: Where is it weak?

–Mitigating factors and hidden data

–An expert can help you identify cliffhangers and loose rocks that might not have been apparent

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A LOT DEPENDS ON SKILL LEVEL Analytics and Scientific Support

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Hand Holds & Toe Holds

• Vehicle recall data base • Telephone records • Weather reports (Historical) • Sun Position and Effects • Commercial driver records • Black box downloads • Testing instruments (force, friction, pressure,

acceleration, speed, time, etc.) • Recognized standards (NHTSA, IIHS, SAE…) • Vehicle Specifications • Detailed first-hand inspections and testing

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EXPECT YOUR EXPERT WILL REQUEST…

• Reports

• Witness statements

• Pictures

• Depositions

• Damages, personal and property

• Any other information you have gathered

• AND, your questions!

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YOUR EXPERT SHOULD THEN GIVE…

• A summary with POV (Point Of View-perspective)

• A Gap Analysis

• An investigative work plan, schedule and budget to fill the known gaps

• Ideas where unknown factors might be important, or become important

• Applicable standards, data and testing data to be evaluated

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COMMON TASKS IN WORK PLAN

• Site inspection • Vehicle inspection • Search and Review of applicable standards

– NHTSA/SAE/IIHS/ANSI/ASTM/IEC/EC/UL/CE/CSA – What are standards? (consensus) – How does that help?

• Analysis, Modeling, Reconciliation, Conclusion • Reporting, Preparing exhibits • Deposition • Trial

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SITE INSPECTION

• 6 DIMENSIONAL X,Y,Z,α,β,ζ

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BEFORE THE SITE INSPECTION

• Provided pictures are first but often misleading – Important

– But, scope limited

– Often, to close for geographic context (big picture)

• (My) First inspection is flat & digital from Google Maps – quick & inexpensive

• Second inspection using Accident Reconstruction Software - Also quick and inexpensive – ARAS HD, but there are others (Mapscene, PC-CRASH, etc.)

– Compare Google maps and ARAS HD

– 8 drivers who blindly followed gps

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MISLEADING PHOTOS

• Photography

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THE SITE INSPECTION

Its about detail • Dimensions • Angles • Friction • Structures • Vegetation • Curbs and sidewalks • Control signs • Anything that can impact the incident!

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MEASUREMENT CAN BE SIMPLE

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MEASUREMENT CAN BE COMPLEX

• Ground measurements are 3D (x, y and z) – Point to point using survey equipment (standard approach)

– Point cloud using automated scanners (latest technique)

– Often surveys are done before the expert gets involved and the expert needs to be able to use them

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OFFICIAL (REAL TIME) SITE INSPECTION

• PTP

• Point Cloud

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THE AR SITE INSPECTION

• Often months to years after the incident • Starting questions are developed from Google and 3D CAD modeling • On scene measurements

– Physical dimensions – COF measurement-drag sled – Acceleration measurement – Geography, east, west and height

• Photographs –then and now comparison important – changes to the landscape

• Surfaces • Repairs • new structure • improvements made in response

– Situational differences • dirt, grass, gravel • Environment, light and shadow, water, other

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THE AR SITE INSPECTION

• Use 3D CAD (ARAS HD) and explore/simulate

• Create 3-D features if needed

• Possibly create a 3D landscape

• Create a video

• Show views from different positions (POV)

– Validate or refute witness statements

– Demonstrate driver POV

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THE VEHICLE INSPECTION

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THE VEHICLE INSPECTION

• Pictures worth a 1000 words • Measurements using Photogrammetry both

before and after inspection-invaluable • Progress of destruction (in this NEXT case, not

just impact damage but trapping/ripping of the vehicle. Important in multi vehicle collisions

• Possible energy loss calculations due to metal bending

• Automated inspection using a point cloud can allow for automated crush analysis of energy

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Multi Vehicle Incident

• Who hit who when?

• Timeframes can be milli-seconds 31

Photogrammetry • Determining dimensions based on existing photos

• More photos improves accuracy

• It’s trigonometry

Calculated Actual Front corner of the book 4.25”, 35” 4.5”, 36” Rear corner of book 8”, 24.75” 8”, 27”

0,0

FRONT REAR

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STANDARDS & DATA

• Search for and Review of applicable standards – NHTSA/SAE/IIHS/ANSI/ASTM/IEC/EC/UL/CE/

– Standards and Data

– What are standards? • Generally Voluntary but can become law –public good – you must

have air bags!

• Contributory

• Represent opposing points of view of interested parties

• Consensus – must have air bags but not told how to build them

– If voluntary, how does that help? • Best thinking of the best thinkers

• If not this, then what?

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STANDARDS & DATA

• Standardized crash test reports – http://www.iihs.org/iihs/ratings/vehicle/v/chevrolet/equin

ox-4-door-suv/2012

• Narrow frontal (pole) crash • Side impact crash • Crush data • Vital statistics of manufactured autos

– Weight, front and rear track, overhang, CG – Moment of inertia - three axis – 4N6xprt; manufacturer’s and more data – ARAS HD

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HOW FAST?

• From skid marks

• From amount of crush

• From spent energy

• From vault

• From video

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MODEL DEMO

• Go to ARAS models

– Model 88th and Riverside

– Model Brisbane, Australia

– Make a new model from audience input

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Useful Websites

• National Highway Traffic Safety Administration-NHTSA http://www.safercar.gov/ • Insurance Institute for Highway Safety-IIHS http://www.iihs.org/ • FARO HD (ARAS HD) http://www.aras360.com/products/software/aras360-hd.html • 4N6xpt (Forensics Experts) http://ews-4n6xprt.com/ • REC-TEC http://www.rec-tec.com/ • Society of Automotive Engineers-SAE https://www.sae.org/ • American National Standards Institute-ANSI https://www.ansi.org/ • American Society for Testing Materials-ASTM https://www.astm.org/ • National Safety Concil NSC

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SURVEY

• Improve your understanding of AR?

• What is the most important thing you can do for me as your AR?

• Your Questions today?

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These principles apply to most any PI type case, or mechanical

engineering situation

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THE END