TRAFFIC ACCIDENT INVESTIGATION Flashcards
ACCIDENT REPORT FORM INV.2 0 5 0 . 1 0 1
The cadet will demonstrate the proper method to completely and accurately fill out
the state accident (DI-9) report form.
♦ Using provided crash information, the cadet will complete an accident
investigation DI-9 report form
♦ The traffic accident investigator’s crash report instruction manual is available
to all law enforcement agencies in an electronic pdf document format
CALCULATIONS INV.2 0 5 0 . 1 0 2
The cadet will identify and demonstrate the proper use of the calculator, template, and
nomographs for determining reconstruction formulas, to include:
♦ Speed of a vehicle from straight skids
♦ Speed of a vehicle from a critical curve
♦ Total speed of a vehicle using the combined speed formula
♦ The radius of a curve
♦ Determine miles per hour
♦ Determining feet per second
♦ Combining the speeds of multiple surfaces
♦ Determining the reaction distance for a given speed
♦ Determine point of perception
♦ Skid to stop distance
♦ Identifying the point of impact in a collision
STOPPING FACTORS INV.2 0 5 0 . 1 0 3
The cadet will identify the factors that influence overall stopping distance of a
vehicle, to include:
♦ Vehicle condition • Brake system • Tires ♦ Road condition • Asphalt • Concrete • Gravel • Dirt ♦ Weather condition • Snow • Rain • Ice ♦ Speed ♦ Operator condition • Impaired • Distracted
ACCIDENT SCENE HAZARDS INV.2 0 5 0 . 1 0 4
The cadet will identify common accident scene hazards, to include:
♦ Fuel spills ♦ Hazardous cargo ♦ Vehicle fires ♦ Moving traffic ♦ Blood/bodily fluids ♦ Power poles, cracked or sheared/downed power lines ♦ Unstable vehicles ♦ Debris
INVESTIGATION TOOLS INV.2 0 5 0 . 1 0 5
The cadet will identify those materials necessary to complete the investigation of
traffic accidents, to include:
♦ Measuring tape ♦ Roll-O-Meter ♦ Traffic cones ♦ Flares ♦ Calculator or nomographs ♦ Diagram forms ♦ Accident report forms ♦ Road chalk/paint ♦ Camera/tripod ♦ Accident template ♦ Witness statement forms
MOVING VEHICLES INV. 2 0 5 0 . 1 0 6
The cadet will identify the circumstances that may allow the movement of vehicles
from an accident scene, to include:
♦ Minor damage
♦ No injuries
♦ Dangerous traffic conditions
NOT MOVING VEHICLES INV.2 0 5 0 . 1 0 7
The cadet will identify the circumstances that would not allow vehicles to be moved
until a thorough investigation is completed at an accident scene, to include:
♦ Death involved
♦ Serious injuries
• Possible extrication
♦ Extensive property damage
SKI D TEST INV.2 0 5 0 . 1 0 8
The cadet will identify the conditions for performing a skid test at an accident scene
to determine the drag factor. Cadets will identify the proper steps in performing a
skid test as follows:
♦ Vehicle in proper condition
♦ Surface in question adjacent to the scene
♦ Known speed
♦ Panic stop
♦ Measure distance
♦ Drag factors are used with suspect skid marks to determine minimum speeds
SKI D MARK IDENTIFICATION INV.2 0 5 0 . 1 0 9
The cadet will identify the different types of skid marks to include:
♦ Side skid ♦ Locked wheel skid ♦ Impending skid ♦ Centrifugal skid ♦ Acceleration skid
MEASURING SKID MARKS INV.2 0 5 0 . 1 1 0
The cadet will identify and demonstrate the different methods of measuring skid
marks using the following:
♦ Measuring tape
♦ Roll-O-Meter
♦ Identification of the “fade” portion of the skid
• Fade is the early or beginning portion of a skid mark that is the first part of
the mark to disappear.
NEWTON’ S LAW INV.2 0 5 0 . 1 1 1
The cadet will identify Newton’s Law of Motion as it pertains to a vehicle at rest or in
motion.
♦ Newton’s First Law of Motion
• Every object remains in a state of rest or uniform motion (constant velocity) unless it is acted upon by an external unbalanced force
♦ Newton’s Second Law of Motion
• A body of mass “m” subject to a force F undergoes an acceleration “a” that has
the same direction as the force and a magnitude that is directly proportional to the force and inversely proportional to the mass, i.e., F = ma
♦ Newton’s Third Law of Motion
• States, for every action (force) in nature there is an equal and opposite reaction
PROTECTING ACCIDENT SCENE INV.2 0 5 0 . 1 1 3
The cadet will identify the proper method for protecting an accident scene.
♦ First priority of initial officer on scene is to provide scene protection to help prevent the crash scene from becoming worse
♦ Use of patrol vehicle to provide protection from oncoming traffic
♦ Use of cones/flares
• Cone patterns to maximize scene safety
♦ Accident scenes are to be treated like crime scenes
• Protect evidence
TRAFFIC CONTROL INV. 2 0 5 0 . 1 1 4
The cadet will identify the most logical points to stop/alter traffic.
♦ Where natural gaps occur
♦ Behind slow moving vehicles
♦ Others
♦ Routing traffic around the accident scene
♦ Do not create “islands” or split traffic around an accident scene
TRAFFIC FLOW SIGNALS INV.2 0 5 0 . 1 1 5
The cadet will identify the proper hand and arm signals.
♦ Start traffic
♦ Stop traffic
♦ Speed up traffic
♦ Slow down traffic
CLOSING TRAFFIC LANES INV.2 0 5 0 . 1 1 6
The cadet will identify the proper positioning of traffic cones and flare patterns to
most effectively direct or stop the movement of traffic in the following situations:
♦ Single lane of traffic
♦ Multiple lanes of traffic
♦ Divided highways
♦ Interstate Highways
