Unit 2-Analyze Collision Components Flashcards
Accident
An accident is a sequence of events that usually produce UNINTENDED injury, death or property damage. pg 17
Collision
A collision is the act of COMING TOGETHER with sudden violent force. pg 17
THE INVESTIGATIVE PROCESS
Fact finding, not fault finding
Establish the Facts
Impartiality in mind pg17
Unsafe Acts and Conditions
Unsafe acts: Includes driving while impaired, speeding, and aggressive driving.
Unsafe conditions: Includes road work in progress, weather related problems such as ice and snow on the roadway, and dense fog that limits visibility. pg 18
THE FIVE LEVELS OF COLLISION INVESTIGATION
Level 1—Reporting Level 2—On-scene Level 3—Technical Evaluation Level 4—Professional Reconstruction Level 5—Cause Analysis pg18
Level 1—Reporting
Reporting is the basic data collection intended to IDENTIFY and CLASSIFY the components of a collision. pg18
Level 2—On-Scene
The On-Scene Investigation is the urgent data collection level and is the MOST IMPORTANT of all five levels. This is the level where the investigator(s) examines evidence, make records of the collision, and obtains additional information that may not be available later. The scene is as fresh and untainted as it will ever be. pg18
Level 3—Technical Evaluation
The technical evaluation is accomplished for SPECIFIC PURPOSES, such as form legal purposes and other data relating to a collision. It also includes completing the following: Scale diagram Damage evaluations Simple speed estimates Tire and lamp evaluations pg19
Level 4—Professional Reconstruction
Professional reconstruction is the effort to determine how the collision happened, if possible. It involves fitting together pieces of information. pg19
Level 5—Cause Analysis
Cause analysis is the final level of collision investigation. The purpose of cause analysis is to determine WHY the collision OCCURRED. pg20
5 MAJOR EVENTS OF A COLLISION
- Point of possible perception
- Point of actual perception
- Point of no escape
- First harmful event
- Point of final rest.
Point of Possible Perception
the position or point where a normal driver could POSSIBLY have perceived the impending hazard. This point will be present in all collisions and may be approximated with adequate investigation. pg21
Point of Actual Perception
The point of actual perception (POAP) relates to the point where the driver ACTUALLY perceived the hazard. This is normally indicated by combining skid marks with reaction distance to show the driver’s estimated point of reaction. This point is not present in all collisions. pg21
Point of No Escape
The point of no escape is the point where the collision CANNOT BE AVOIDED by one or more traffic units. The point of no escape is present in all collisions and is at times difficult to locate, depending on the circumstances of the collision. pg21
First Harmful Event (Point of Impact)
The FIRST HARFUL EVENT is the first contact between two traffic units, between a traffic unit and another object, or first contact with a highway surface during an overturn.
Point of impact
Identifies the point that the components SUSTAINED DAMAGE. When it is the first point where the vehicle contacts the point of perceived danger (sustaining
damage or not), it is called the primary point of impact (PPOI). pg 21
Point of Primary Contact
The FIRST CONTACT between two traffic units, between a traffic unit and another object, or first contact of a vehicle with a highway surface during an overturn. pg21
Point of Maximum Engagement
The point of maximum PENETRATION or engagement by one object into another such as the maximum penetration of one traffic unit into another traffic unit or object during collision. pg21
Point of Disengagement
The SEPARATION of two objects, for example, traffic units, after maximum engagement. pg21
Point of Final Rest
That point where all traffic units come to a final position after all movement has stopped. The point of final rest may be controlled or uncontrolled, and is present in every collision. pg22
What is a Controlled movement?
Component is moved by OUTSIDE SOURCE after impact. The driver moves the vehicle off the roadway. pg22
What is a Uncontrolled movement?
Component continues to roll, slide or flip after the impact. NO outside source controlling the final rest position. pg 22
What is a factor of Impact?
Impact involves forces between a vehicle and some other object. pg22
What is a factor of Forces involved?
These forces can change speed, direction, rotation or all of these. pg 22
What is a factor of Friction?
Friction forces can change the speed and direction of a vehicle (i.e., braking and/or turning). pg22
What are the TWO COLLISION CAUSES
There are two sub-categories for collision causes: Operational and Conditional. pg24
Operational Factors of a collision cause are?
Operational factors in collisions are ones that the driver CAN control or change. There are three operational factors as follows.Trip Preparation, Driving Strategy, and Evasive Actions pg24
Conditional factors of a collision cause are?
Are factors over which the driver has NO CONTROL or cannot change. There are three conditional factors as follows. People, Roads, Vehicles pg24
What are the COMPONENTS OF THE HIGHWAY TRANSPORTATION SYSTEM?
- People - Drivers, pedestrians, occupants, witnesses, and acquaintances.
- Roads - Any and all highways, roads, farm to market (FM’s) etc.
- Vehicles - Any and all vehicles operated upon the roadways. pg25
what are FOUR KINDS OF INFORMATION DOCUMENTED FOR EACH COMPONENT?
- Identification.
- Description.
- Condition Prior to the Collision.
- Results of the Collision on the Component. pg25
What are some conditions of the people component prior to the collision?
Open food containers
Beer cans/liquor bottles
Medication/drugs
Open maps pg26
What are some examples of driving impairment?
Alcohol Drugs/medication Carbon monoxide Drowsiness/sleep sudden disablement pg26
What are Motives and Attitudes
Attitudes: express how a driver THINKS and feels about driving
Motives: explain why a driver TRIES to drive a certain way pg26
Results of the Collision on the People Component: No Injury
No bodily harm pg27
Results of the Collision on the People Component: Possible Injury
Reported or claimed, but not meeting the other injury classifications. These include momentary unconsciousness, whiplash, limping, nausea, and hysteria pg27
Results of the Collision on the People Component: Non-Incapacitating/evident injury
Other than fatal or incapacitation which, at the scene of the collision, is evident to a person other than the injured. Includes a lump on the head, abrasions, bruises, cuts, and scratches pg27
Results of the Collision on the People Component: Incapacitating Injury
Prevents the person from walking, driving, or continuing with normal activities that person was capable of just before the collision. pg27
Results of the Collision on the People Component: Fatal Injury
Results in death within 365 days after collision. Federal law states that if a person dies within 365 days of the collision, and that death is a result of injuries sustained in that collision, then that collision must be categorized as a fatal injury collision pg 27
Driving Process: Strategy
Involves GENERAL PERCEPTION of possible hazards and the action taken to minimize the risks pg27
Driving Process: Solid Driving Strategy
RARELY involves quick decisions. pg27
Driving Process: Tactics
require QUICK DECISIONS and are actions taken by a driver to escape a collision such as steering right or left, accelerating, decelerating, and backing up and simply doing nothing at all pg 27
Driving Process: Reaction Time
Reactions is a person’s voluntary or involuntary RESPONSE TO A HAZARD. The normal time it takes from perception to a reaction is 1.6 SECONDS pg27
What is the term AT INTERSECTION?
If the first harmful event occurs within the limits of an intersection (inside the intersection) pg29
What is the term ON INTERSECTION?
Indicates that the collision occurred on the approach to or exit
from an intersection.(outside of intersection) pg29
What are the SIX physical signs regarding a collision that should be documented?
- Final rest
- Tire/skid marks
- Metal scars
- Debris
- Fixed objects
- Vaults and falls pg31
What is a Cook/Scrub?
SUDDEN CHANGE during skid because of impact. Noted as collision scrubs pg32
What is are Yaw marks/Critical speed Scuffs?
The wheel is rotating and slipping sideways parallel to the axel pg32
What is the action of Slide Slipping?
Cause by road configuration and weight shifting forwards and sideways pg32
What is a Spin Skid?
Results when a vehicle rotates around its center of mall, as in cases where the rear wheel move in a manner so as to lead the front wheels, and in case where there is an external force applied to a vehicle at a location other than in direct line with its center of mass. pg 32
What is a Gap Skid?
Made by releasing and re-applying brakes. Gap is at least 10ft pg32
What is an Overlapping Skid Mark?
Caused by all four or two tires on the same side locking up at the same time pg32
What are the Damage Classifications?
- No damage noted or observed.
- Other damage is that damage done which affects only the load or the appearance of the motor vehicle.
- Functional damage is any non-disabling damage which affects operation of the motor vehicle or its parts.
- Disabling damage is any damage to a vehicle in such a manner that it cannot be legally driven, or damage to a trailer such that it cannot be towed in the usual manner during daylight after simple repairs.
What are the capabilities of the Total Station?
- Accurate on-scene diagramming/
measurements. - Download of information to computer.
- Rapid diagramming – Measures with or without
prism. - Integrated Measurement System -
The system will calculate measurements based
upon information inputted by the user. pg48
What is the purpose of the M-FX Data Collector?
It is a very powerful, easy to use DATA COLLECTOR that supports total stations from Nikon, Sokkia, Topcon or Leica. It is the
most convenient way to transfer data from a total station to the FX3 diagram, which will automatically draw your scene. pg48
What are the pros of the FX3 Software/Program
Basic Diagramming .Selecting/Placing/Adding/ Editing Objects and Symbols .Drawing . Adding text . Smart Corners pg51
What is the purpose of the Traffic Template?
The purpose of the traffic template is to AID in preparing field sketches and scale diagrams and is
helpful for simplifying ROUGH on-scene calculations. pg52
What is the preferred method of measuring a traffic collision and why?
Grid/Coordinate Method:
.Accuracy,
.You can make measurements on the shoulder or roadside
.You can make measurements with minimum exposure to the traffic
conditions.
.Easier to draw to scale than when using triangulation method pg54
When would one use the Triangulation Method?
.Edges of the roadway are difficult to locate or are covered.
.Points to be located are MORE THAN 30 feet off the roadway. (insure two RP are established 20-50ft apart)
.Roadway edges are irregular as in traffic circles and some complicated junctions.
.Objects are off the road in woods or swamps.
measurements.
.There are no clear roadway edges for reference lines. Problem areas are construction sites, gravel pits, large parking lots or open fields. pg56
When would you MEASURE USING ONE POINT?
-Gouges or groups of gouges, grooves and tire marks, spatter or puddles all LESS THAN 3ft across pg58
When do you MEASURE WITH TWO POINTS?
Vehicles, Human bodies, Straight tire marks, Curved tire marks more than 3-8ft long, straight grooves more than 3ft, Dribble path. pg59
What is a tangent?
Where the STRAIGHT LINE ENDS and the curve begins. pg68
What is a Chord?
A straight line distance BETWEEN TWO POINTS on a curve (can be between the two tangent points. pg68
What is a middle ordinate?
The distance at HALF of the chord to the outside edge of the curve. pg68
