A Training Guide For
Traffic Crash
Investigations
A Training Guide for
Law Enforcement Officers
Wisconsin Department of Justice
Law Enforcement Standards Board
December 2009
The Law Enforcement Standards Board approved this textbook
on December 1st, 2009.
Training Academy effective date is May 1, 2010.
All law enforcement basic preparatory training courses that begin on or after May 1st, 2010, must incorporate this updated textbook and any related updates to the curriculum.
Courses beginning before that date may elect to use these updated materials.
ACKNOWLEDGEMENTS
Many people have contributed to the writing of this manual. The Training and Standards Bureau, Wisconsin Department of Justice gratefully acknowledges the dedication of the Patrol Procedures Advisory Committee, which has worked long and hard to revise the content of earlier manuals and develop new content for the present guide. The current members of the Committee are:
Designated Representatives
Jeff Pettis, Sheriff’s Representative
Tom Winscher, Chief’s Representative
Clark Pagel, Wisconsin Technical College System
Paul Matl, Wisconsin State Patrol
Craig Henry and Chance Bamba, Milwaukee Police Department
Doug Funk, Milwaukee County Sheriff’s Office
Sherri Strand, Madison Police Department
Stephanie Pederson, Training and Standards Bureau (Chair)
Practitioners
Monica Barman, Sun Prairie Police Department
Bruce Buchholtz, Platteville Police Department
Steven D. Hausner, Burlington Police Department
Ken Pileggi, Mukwonago Police Department
Deanna Reilly, Madison Police Department
Tom Witczak, Fox Valley Technical College
Hammond, Ken, Training and Standards Bureau
Emeritus (non-voting) Members
Colleen Belongea
Timothy Hufschmid
Jay Iding
Bernie Kocher
Dave Mattheisen
Robert Miller
Mike Murray
Richard Nichols
TABLE OF CONTENTS
INTRODUCTION 1
TRAFFIC CRASH INVESTIGATION 1
Levels of Investigation 2
At-Scene Investigation 2
Advanced (Technical) Investigation 2
Collision Reconstruction 4
Traffic Crash Investigation 4
Investigator Qualities 5
INVESTIGATING CRASHES 7
REQUIREMENTS OF REPORTING CRASHES 7
Wisconsin Statutes Regarding Accidents and Accident Reporting 7
RESPONDING TO CRASHES 10
Incident Response 10
RESPONDING TO THE SCENE (Report) 11
Arriving at the Scene 11
EVALUATION OF THE SCENE (Evaluate) 12
SCENE STABILIZATION (Stabilize) 12
PRESERVE LIFE AND EVIDENCE AT THE SCENE (Preserve) 14
Operator, Passenger, and Witness Interviews 14
Vehicle and Occupant Restraint System Inspection 16
MECHANICS OF MEASURING AND DOCUMENTING CRASH SCENES 19
MEASURE AND DOCUMENT THE CRASH SCENE (Organize) 19
Results at a Crash Scene 20
Vehicle Position 20
Debris areas 20
Road Marks 23
Meanings of Marks 30
LOCATING SPOTS FOR EACH RESULT 30
MEASUREMENT SYSTEMS 32
Coordinate System 32
Triangulation System 34
Combination of Systems 36
MARKING SPOTS ON THE ROAD AND ROADSIDE 37
Marking Supplies 37
Marking Spots 37
CRASH SCENE DIAGRAMS AND SKETCHES 39
Field Sketch 39
Labeling 43
RECORDING BASIC MEASUREMENTS 46
Table of Measurements 46
MEASURING 47
Measuring Devices 48
Using Measuring Tapes 49
Reading Tapes and Recording Measurements 50
Electronic Measuring Devices 51
ADDITIONAL AND SUPPLEMENTAL MEASUREMENTS 52
LABELING AND REVIEWING THE FIELD SKETCH 53
AFTER-COLLISION SITUATION MAPS (SCALE DIAGRAM) 53
Templates 54
Return the Scene to Normal (Normalize) 55
SUMMARY 56
WISCONSIN MOTOR VEHICLE ACCIDENT REPORT 59
OVERVIEW OF WISCONSIN ACCIDENT REPORTS (Document and Debrief) 59
Wisconsin Motor Vehicle Accident Report Form (MV4000) 59
Driver Report of Accident Form (MV4002) 67
Badger TraCS and the MV4000 69
DRIVER, VEHICLE, ROADWAY, AND ENVIRONMENTAL CONDITIONS AND FACTORS PRIOR TO THE COLLISION 71
Driver Condition 71
Roadway Conditions 71
Environmental Conditions. 73
CONTRIBUTING CIRCUMSTANCES TO A CRASH 73
Driver Factors 74
Vehicle Factors 74
Highway 74
SUMMARY 74
PHOTOGRAPHING THE SCENE 77
CRASH SCENE PHOTOGRAPHY 77
“AT SCENE” PHOTOS 78
Basic “At-Scene” Photos 78
Photographing Vehicle Damage 80
Procedures for Photographing a Crash Scene 81
OTHER CONDITIONS DEALING WITH PHOTOGRAPHY 82
TIPS/Techniques 82
SUMMARY 83
APPROPRIATE ENFORCEMENT ACTIONS 85
PROCEDURES TO DETERMINE SPEED ESTIMATES 85
ENFORCEMENT ACTIONS 85
ENFORCEMENT DECISION 86
OPTION #1: No Formal Enforcement Action 86
OPTION #2: Issue a Traffic Citation 86
OPTION #3: Criminal Violations 87
Non-Contributing Violations 87
HIT-AND-RUN INVESTIGATIONS 88
SUMMARY 90
APPENDIX A - GLOSSARY 91
APPENDIX B - Wisconsin 2008 Traffic Crash Figures 103
APPENDIX C – SLIDE-TO-STOP SPEED ESTIMATES 105
REFERENCES 107
ii
December 2009
INTRODUCTION
TRAFFIC CRASH INVESTIGATION
Our entire nation is a “nation on wheels.” Over 188 million motor vehicles and more than 170 million licensed drivers travel over two trillion miles a year on our streets and highways. [1] Hazardous materials are transported on these roads every day and thousands of people are killed in crashes on our streets and highways every year. Traffic jams and delays caused by traffic crashes during rush hour result in millions of dollars and hundreds of thousands of productive hours lost to the economy and unnecessary environmental pollution each year.
In 2008, 37,261 people were killed in the estimated 5,811,000 police reported motor vehicle traffic crashes, 1,630,000 people were injured, and 4,146,000 crashes involved property damage only.[2] Since more people are killed and injured and more economic loss is suffered due to traffic crashes then all other types of crashes combined, the importance of traffic crash investigation cannot be overstated. The objective of this type of investigation ranges from providing the basic police functions, the protection of life and property, to restoring the flow of traffic.
A vehicle collision, regardless of driver intent, is referred to as a “crash” because the primary cause or causes typically result from specific driver actions. Traffic crashes are not accidents; they are avoidable events caused by a single variable or chain of variables.
There are three basic elements involved in any crash. The first is people. This includes, but is not limited to experience, impairment, and actions. The second is vehicles which includes, but is not limited to, size and equipment. The third and final element is the roadway. It also includes, but is not limited to weather (wet, dry, snow) and road conditions (road construction, debris). The investigating officer of the crash will have to locate and preserve any evidence from the collision found in or on the roadway.
Traffic crashes are extremely confusing events. How they occur, who or what caused them, and why they occurred are facts law enforcement must determine. Every officer must know the fundamentals of traffic crash investigation and know how to prepare traffic crash reports. Law enforcement officers spend a lot of time responding to, managing and investigating crash scenes. The Wisconsin MV4000 Report officially records events surrounding a crash. The accuracy and completeness of the report will depend on the quality of an officer’s investigation and his/her attention to detail. This area of instruction will introduce you to the necessity for accurate, impartial and professional traffic crash investigation and reporting.
Each subsequent level of investigation relies heavily on the quality of the initial investigation. The location of the crash, road conditions at the time of the crash, and other evidence at the scene cannot be replaced or recreated, unless documented by the officer during the at-scene investigation. The public, insurance adjusters, the Department of Motor Vehicles, and other involved personnel will see the results of the crash investigations. The quality of an officer’s work will reflect directly upon him/her as the investigator and on their agency.
Levels of Investigation[3]
The severity and circumstances of a collision will determine the proper level of investigation. In their order of complexity, the levels are usually called at-scene investigation, advanced (technical) investigation, and reconstruction.
At-Scene Investigation
The first level of investigation is the at-scene investigation. When a basic crash occurs, the first responding officer will conduct this level of investigation and file a standard crash report. The at-scene investigator will collect evidence and document the scene.
The officer’s first task is to make the scene safe and prevent a second crash. Traffic must immediately be redirected. Next the officer must care for the injured and request additional resources if needed. Finally the officer will observe and record the facts pertaining to the collision. These include taking measurements, documenting other evidence at the scene, and completing a field sketch. The investigation may include taking photographs, checking all drivers for intoxication or other impairment, completing a Wisconsin Motor Vehicle Accident Report (MV4000) form, and other investigative reporting and documentation. The at-scene investigation is primarily concerned with data gathering and recording the scene.
Advanced (Technical) Investigation
At-scene investigations should be conducted for every collision. Advanced investigations are undertaken whenever the data obtained at the at-scene level is insufficient to complete the investigation. The purpose of the advanced investigation is to collect additional data for determining the charges to be brought against one or more of the individuals involved, for litigation reasons, or for laying the foundation for the next level of investigation – reconstruction.
Unlike the at-scene investigation, which is initiated immediately or as soon as practicable after the collision, the advanced investigation may take place at a later time. Data from the at-scene investigation will be reviewed. Since much of the evidence at the scene may already have disappeared, the advanced investigation may depend heavily on the completeness and accuracy of the data recorded in the at-scene investigation.
During the advanced investigation the investigator is expected:
· To determine the drag factor of the skid surface(s) and the minimum initial speed of each vehicle (unless already calculated in the at-scene investigation);
· To determine time-distance relationships and solve momentum problems;
· To match marks on the roadway with the parts on the vehicle causing damage, to determine the point of impact;
· To determine what is impact damage to the vehicle and what is contact damage;
· To match the damaged areas of the vehicles to determine the principal direction of force (PDOF);
· To correlate injuries with the parts of the vehicle impacted by the occupants (occupant kinematics);
· To determine if headlamps and other lamps were ON or OFF at impact;
· To determine if any fire damage occurred before or after impact;
· To determine if mechanical or electrical failure contributed to the crash (this may require the help of a specialist); and
· To prepare a scale drawing of the scene from measurements and notes made at the scene.
Officers need to attend advanced training to learn the techniques used by the advanced investigator. A perquisite is usually the completion of a basic collision investigation course or several years of practical experience in at-scene investigation.
Collision Reconstruction
Reconstruction is the highest of the three major levels of investigation and is usually undertaken only in support of litigation or research. Its main purpose is to determine how the collision occurred. It deals primarily with direct and immediate causes of the crash. These frequently entail behavioral errors on the part of the drivers.
Reconstruction expands on all the principles of at-scene and advanced investigation. It may involve experiments to ascertain performance and other capabilities of the vehicle, or to determine driver and pedestrian behavior. Reconstruction entails assembling all the technical data required to build a case for court.
Although a reconstructionist usually has greater depths of knowledge and broader experience than an investigator qualified only in at-scene or advanced investigations and can make more inferences from existing data, he/she is very dependent on the thoroughness and quality of the investigations conducted at the scene, and may have to work largely with the evidence that has been preserved and recorded earlier.
Traffic Crash Investigation
It is important to respond to crashes and to prevent further collisions. Your basic function as the responding officer is the protection of life and property. As the first responder, you have to protect your life as the top priority when responding to crashes. If you do not respond to the scene safely and protect yourself and the scene, you are of no value to anyone.
Often officers raise the objection that crash investigations merely do the job of the insurance companies. While it is certainly true that the insurance companies benefit from a good investigation, the fact that a traffic and/or criminal law may have been broken puts the responsibility directly in the lap of law enforcement to gather evidence for prosecution.
You have a responsibility to properly record all of the facts surrounding the crash. You may well be the only emotionally and financially detached person on the scene; therefore, your report of the event is logically the most accurate rendition of the event. All conclusions and any enforcement action you take must be based on the facts, evidence, and statements you personally gather or know to be true.
During the crash investigation, you have to determine the cause or causes of the collision. While the train of thought is that placing blame is not an objective of crash investigation, determining the cause or causes may in fact determine who bore the responsibility for the event.
Investigator Qualities
The qualities of a good crash investigator are those traits, both personal and professional, that the officer displays on each scene. You must be enthusiastic, sincere, responsible, and impartial when investigating a crash. You will find that traffic crash investigation, in real life, will sometimes be a fairly unpleasant task. Seldom will the people involved in the crash have anything to be happy about. However, the information in your reports may be useful in preventing future crashes through the application of education, engineering and enforcement. Some of the qualities you need to exhibit while investigating a crash will assist you in effectively completing the investigation while presenting a professional image of the law enforcement profession.
Many crashes occur in bad weather, resulting in you having to work while standing in the rain, bitter cold, or extreme heat. Through it all, you must not make a mistake or fail to carry out your assigned duties. The citizens you will be working with at the scene may be emotional, some may be rude, or they may be obnoxious. Because you are human, your initial response may be to lash out in anger, however, as a professional officer, you must try to rise above your frustration and anger and realize that this is an upsetting situation for the people involved in the crash.
You need to investigate all crashes thoroughly no matter how minor. It is easy for an officer to procrastinate and do the minimum acceptable on minor crashes. This is unacceptable to the people we serve. To the people involved, our customers, this is a very traumatic event. A motor vehicle is one of the single largest investments in many people’s lives and a major purchase to all. You need to show sincerity to the parties involved. For the people involved in a crash, this may be one of a very few contacts with law enforcement. You have it within your power to reap public support or lose it based on the level of professionalism you display.