training materials for accident reconstruction

392 Pages·2005·20.59 MB·English

TRAINING MATERIALS FOR
ACCIDENT RECONSTRUCTION
REFERENCE MANU~L
Volume I
First Edition
Kenneth L. Campbell
Peter Cooley
Robert L. Hess
Robert E. Scott
Christopher B. Winkler
Edited by
Kenneth L. CqbelZ
Thomas L. !cDoZ e
HIGHWAY SAFETY RESEARCH INSTITUTE
The University o f Michigan
Ann Arbor, Michigan 48109
May 1979
Prepared for the Department of Transportation, National Highway
Traffic Safety Administration under Contract No. DOT-HS-8-07968.
This document is disseminated under the sponsorship of the
ijepartment of Transportation in the interest of information
exchange. The U.S. Government assumes no liability for the
contents or use thereof.
I I
1
4. Titlo 4S ubtitle 5. Rqrt Date
Training Materials for Accident Reconstruction
Vol ume 1- -Reference Manual
, I. P..kriaq O&zd.r Repm No.
K. L. Campbel I , Peter Cooley, Robert L. UM-HSRI-79-27-1
?. MW*)
,Hess, Robert E. Scott, Christopher B. Winkler,
9. Prirring O r m i ~ d r -4 U*Oa*n*d f homas L. Mc-01 e 10. worb Unit NO.
Highway Safety Research Institute
The University of Michigan 11. Contrmct w Gvmt Me.
DOT-HS-8-01968
Ann Arbor, Michigan 48109
13. T .II 01 RW d Poriod b-4
Final Reference
11. sqmnaiy~~woad~--
U .S. Department of Transportation Manual
National Highway Traffic Safety Administration
14. *ruing A m yC da
This Reference Manual is Volume I of the training materials for
a course in Accident Reconstruction for the National Accident Sampling
System. Volume I1 is a Student Notebook, and Volume I11 is an
Instructor's Manual containing 1e sson out1 ines.
This manual attempts to provide a complete background for accident
reconstruction in general and in the use of the CRASH2 computer program
in particular. Background information on scene and vehicle examination,
and basic physics and dynamics are presented prior to the material on
the CRASH2 program.
CRASH2, Accident Reconstruction,
Documentation is available to the
Training Materials
, U.S. public through the National .
I I ~echnicalI nformation Service (NTIS) . 1
I ,
Springfield, Virginia 22161
I 19. karriw Clreil. (04 thin r3rt) II a. S.anw Clomail. (04 this M.) 1 21. No. of Pqes 1 22 Pricm
1 1 I
Unclassified Unclassified
390
iii

PREFACE
This Reference Manual is Volume I of the training materials
developed by the staff of The University of Michigan Highway Safety
Research Institute for investigators in the National Highway Traffic
Safety Administration (NHTSA) National Accident Sampling System
(NASS). Volume I1 is a Student Notebook and Volume 111 contains
lesson out1 ines.
The course was conducted for senior NASS investigators in May
1979. A course evaluation was reported separately (Report No.
.
UM-HSRI-79-87 )
ACKNOWLEDGMENTS
The preparation of these materials and their subsequent
presentation in the classroom could not have been accompl is hed wi th-
out the supporting efforts of the Institute staff. The authors are
particularly indebted to Ms. Leda Ricci, Ms. Sharon Derry, and
Mr. Michael Kubacki for their many hours spent in word processing
and editing. Ms. Kathleen Jackson was responsible for the prepara-
tion of the many i 11 ustrations used, and provided much appreciated
assistance with the final paste-up.
1 SCENE EXAMINATION Peter CooZey
2 VEHICLE EXAMINATION Peter Coo ley
3 DATA DOCUMENTATION Peter CooZey
4 PHYSICS AND DYNAMICS Robert L. Hess
5 ENERGY CONSIDERATION Kenneth L. Campbe lZ
6 VEHICLE DYNAMICS Christopher B. WinkZer
7 TIREMARKS AND ROADWAY Peter Coo Zey
EVIDENCE AND ANALYSIS
8 AN OVERVIEW OF THE OPERATION Robert L. Hess
OF CRASH2
9 APPLICATION Robert E. Scott
10 COLLISION SEVERITY MEASURES Kenneth L. Campbe22
APPENDICES:
A. Radius of Curvature of an Arc
B. Critical Curve Speed
C. Questions Posed by CRASH2
D. Manual Computations for DAMAGE
E. Manual Computations for START2 and SPIN2
i SCENE EXAMINATION
Smary. The accident scene consists of the physical real
estate or area over which the crash occurred-the roadway as
well as the off-road environment relevant to the crash. The
scene is best described as that prtion of the roadway and
off-road environment which begins when and where the vehicle
enters the pre-crash phase and ends a t the final rest
positions of the vehicles. Included in the area are the
vehicles, debris, fluid, deposits, human bodies, human matter,
interior materials from vehicles, components from the
vehicles, vehicle cargo, other vehicles and/or traffic as well
as those prtions of the roadway (signals, signs, markings,
traffic control devices) involved in or relevant to the crash.
The traffic control devices to be included are those which
influence the traffic behavior or vehicle movement prior to
impact. Thus, the scene oftentimes w i l l involve considerable
distances over which the crash vehicles moved both prior to
and following impact.
The accident scene is one of the three major areas to be examined
in an accident. The remaining two areas are occupant and vehicle.
These three areas provide convenient categories into which the
investigator m y address his attention, the collection of data, and the
interpretation of evidence. These basic categories have mple precedent
in previous in-depth accident investigation studies conducted under
contract to the National Highway Traffic Safety Administration. Human
factors, vehicle factors, and envi ronmentai factors combined with the
three phases of pre-crash, at-crash, and pst-crash periods of the
accident make up the well known nine cell matrix (see Figure 1.1) with
i.h ich in-depth accident investigations have Seen conducted for
years.
Two of the factors, scene and vehicie, are the topics of this and a
subsequent chapter. Each chapter w i l l discuss each of the events in
detail as it relates to the gathering of data relevant to the accident
reconstruction process.
bhen conducting accident investigations sometime after the accident
has occurred (not on-scene) the investigator is somewhat limited in what
can be observed reievant to the accident scene as it was to the time of
coliision. In NFSS, for example, most accident investigations are
conducted twenty-four hours (or later) after the accident event. This
means that the investigator nust approach an old accident scene (ivhich
CRASH PHASES
PRE-CRASH CRASH POST-CRASH
HUMAN
VEH ICLi
ENV IR ONMENT
9:tec:imes is marginally identified by the poiice accident report) and
attempt to discern from examination the basic characteristics of the
roadway and off-road enviroment at the time of the crash, and any crash
evidence still remaining on and off the roadway in the crash area. The
first problem is locatiq the boundaries of the exact crash area.
klice accident reports w i l l note key intersecting roadways, as well as
the roadway upon which the accident occurrecl. They w i l l also usually
note the direction a d distance ( in tenths of one miie) from a known
intersection of the roadway on which the crash occurred and the nearest
intersecting roadway. The investigator should be aware that distances
noted on the plice report are often incorrect or lacking sufficisnt
accuracy to enable one to accurately find the location of the crash on
the roadway. Such distances noted on the plice accident report are
often merely readings from the patrol cruiser's odometer, and can mean
the distance from the final rest psition of the vehicle to the
reference intersection, or the point of impact between vehicles to the
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2 SCENE EX4~IYA'ITON