Crash Investigations Flashcards
What is the definition of crash?
An occurrence in a sequence of events involving at least one moving motor vehicle which produces in intended injury, death or property damage
What is the difference between crash and accident?
Crash: someone used poor driving strategies and tactics
Accident: implies no fault
What is crash prevention?
1) traffic enforcement
2) public education
3) roadway engineering
4) visible patrol
5) reporting of hazards
What is pre shift vehicle inventory?
Basic equipment
- measuring tap
- camera
- spray paint/crayons
Must have equipment
- Traffic vest
- fire extinguisher
- first aid kit
What is the percentage of survival if you wear your seatbelt?
80% more likely to survive if belted
What are some hit and run responses?
Obtain as much info as possible on suspect/vehicle and be aware of vehicles that you pass
Be aware of getaway routes
What happens if you crash while in route to a crash?
Someone will have to take the crash you were responding to
Someone will have to respond to your crash
You will have to account for your actions
What are steps to conduct a crash investigation?
Arrive safely
Care for injured
Secure and preserve scene to protect evidence and people
ID involved parties
Inspect the scene
What are traffic crash investigation questions?
Who, what, when, where, why and how…
The crash occurred
What are some things to be aware of with your car when arriving safely?
Is the trunk lid of car covering emergency lights
Proper use of overhead emergency lights
Use all the lights
Keep trunk lid down so lights are visible
What should you do when you arrive at the scene?
Radio your arrival and ems equipment needed
Park in safe position off the roadway or safe position to protect the scene
Make sure your trunk lid is shut and vehicle secured
What is required OSHA safety equipment?
Traffic safety vest
$7,000 fine if caught not wearing it
Makes you more visible
What should you look for when arriving to a scene?
Watch for hazards
- power lines
- fuel
Other types of hazards
- bio
- blood
- body fluids
What are some steps in Determining injuries?
Be prepared to render first aid
Use proper procedures
Call medics if questions about injuries
What is the proper cone pattern?
Taper from curb
Create buffer zone
Extend pattern beyond scene
Cone spacing: 10-30 ft apart and required to be 24” high and have reflecting ring circumventing the cone
What are the regulations with flare use?
OSHA requires flares to be used in conjunction with cones
Flares work better in low light conditions
**do not put flares on roadway evidence **
Space the flares
What If it’s a more serious crash?
Block off entire street and create detour
Methods of blocking road (barricades, cones/flares, crime scene tape)
Other considerations
What is odot incident response unit?
Must notify odot whenever a state highway needs to be closed
Odot has responsibilities/authority over all state roads
Do NOT tell odot your closing their roads
Advise them you would like to close the road and allow odot to order closure
What is the exception to odot incident response unit?
If scene of crash is a crime, develop alternate route plans for traffic
Keep as many lanes open as possible
Once crime scene is collected advise it’s no longer a crime scene
Citizens directing traffic?
If you have a citizen directing traffic, you assume liability
Don’t have them direct traffic
If one is when you arrive, replace them ASAP
How should you document the scene for evidence?
Photographs: take 50% more than you need
Measure the site/scene/evidence
Collect evidence
What are categories of roadway evidence?
Area of impact Tire marks Roadway marks Debris pattern Fluid trails Rest position
What type of conditions should you inspect the scene for?
Physical condition
Roadway conditions
Vehicle conditions
Scene evidence
What are the three major categories of tire marks?
Skid marks
Scuff marks
Rolling print marks
What are skid marks?
A tire friction mark caused by a tire that is locked and sliding
Generally straight
Only one or two skid marks
Start light end dark
Front tire marks should be dark on outside, light to the inside
What are some factors that may cause a skid mark to not travel in a straight line?
Grade or slope of roadway
Unequal road surfaces
Rotating vehicle
Defective breaks
What are the different skid marks on surfaces?
1) Asphalt: oils and tars are brought to the surface by heat
2) Wet asphalt: erasure appearance
3) Concrete: white or like “cleaning” mark
4) Gravel/dirt-form of “furrow” plowing away material
5) Wet grass-matting down, not dig into grass, slide across
6) Ice: shiny and wet-short lives
How do you measure roadway evidence (tire marks)?
Beginning of shadow to end of skid mark
Measure each mark separately
Note overlapping skids in comparison to shadow
What is shadowing?
Mark caused by a tire that is rolling at a speed slower than the vehicle is traveling
Causes right before tired starts to skid
Skip skid marks?
Fully locked tires that are jumping across the surface
Gap skid marks?
Created by applying and releasing breaks
Overlapping?
Trailing tire skids across the lead tire
Rollover Threshold marks?
Marks seen prior to a vehicle rolling over
What is evidence of yaw marks?
A tire rotating and slipping
Parallel stripe marks always curving
Striations
What are Crash tire scuff marks?
Caused by rolling tire that is slipping
Post crash scuffs?
Occurs when a vehicle rotates after impact
Useful for speed calculations
What is front end wheel skids vs rear?
Front wheels skids are darker on outside edges
Rear wheels: darker on inside
What are striations?
Oblique angles
Parallel to plane of axis
Skid marks in line with tire marks
What is the best evidence for roadway marks?
Gouges-deeper and more surface orientated at the end
Tire marks-
Scrapes
What are the two main areas to measure at a scene?
Scene measurement- measurements taken of physical evidence
-roadway/vehicle/physical evidence
Site measurements- measurements of the surrounding area
-shoulders/center line, intersections
What are the three purposes of a field sketch?
Quick overall picture of the scene
Shows what points need to be measured
Start of a permanent record
What type of physical evidence needs to be measured?
Everything
Final rest position location of injured/dead
View obstructions
What are the three types of reference points?
Tangible-an object of permanent location , fire hydrant telephone pole etc
Semi tangible-related to a tangible location
Intangible-no tangible points
What are the two types of measuring applications?
Triangulation: at least two separate measurements from two fixed points
Measure from one reference pint to evidence
Coordinate (baseline): worker friendly measurement, requires straight line created along a base line
*all measurements taken at 90 degree angle
What type of crashes are measured?
All fatal crashes Prosecutable crashes Serious injury Government vehicle Pursuits
If a truck is involved in a crash, what form needs to be used?
Truck collision form
Truck: -having at least 6 tires on road
- Vehicle displaying hazardous place cards
- bus with seating for MORE THAN 15 people including the driver
What are the two reporting requirements?
Citizens report: must report to DMV within 72 hrs when crash involves death/injury or damage exceeding $1,500
Police report: shall complete a report within 10 days
What are two types of impacts?
Centered-impacts through center of mass no vehicle rotation
Eccentric-causes vehicle to rotate around it’s center of mass
What are the levels of investigations?
Basic crash reporting
At scene/technical investigations
Crash reconstruction
What are the two types of main contact damages?
Contact -direct contact with another vehicle, pedestrian, object
Induced damage-non contact damage causes by forces transmitted through the vehicle
-bends/folds of metal
What is windshield damage?
Contact windshield damage-object inside or out striking the windshield-spiderweb appearance
Induced windshield damage-damage to the vehicle other than windshield-parallel fracture patterns
Other glass damage- shattered windows
What are the three events that take place in a vehicle during a crash?
Crash of vehicles-crash of cars, into object etc
Human/interior crash-occupant crashes into an object inside of car
Internal crash-internal organs of the body start to hit other organs
What are proper first aid procedures?
Airway
Circulation
Breathing
What are indentations?
Occurs from a vehicle that flips, vaults or rolls over
What are evidence scratches?
Superficial marks on the surface of roadway
What is evidence of debris?
Good indication of the area of impact
What are the two types of evidence-final resting positions?
Uncontrolled: comes to rest on its own and is not moved from its final test
Controlled: comes to rest in a predetermined location
What type of measurement is not recommended?
Pace method
What is measuring vehicle placement?
Measuring center hubs of vehicles w/a small “T”
At least the hubs on one side of the vehicle
Basic photography, size of objects?
Long range: should encompass the entire scene and reference landmarks
Medium range: more specific points
Close up photos: specific details
Newtons laws?
A body at rest remains at rest and a body in motion remains in motion
A force acting on the body accelerates the body in line with the force
For every action there is an action or opposite reaction
PDOF?
Principle direction of force
Measured in degrees and increases in clockwise direction
Which way will a body move during the force of a crash?
Toward the force of the crash
What are some “people evidence” ?
Windshield
Airbags
Seatbelt’s
What documentation must an officer ask for if a truck driver is involved in an accident?
Medical card if operating under a CDL
Cannot ask for log book unless trained
What are exterior damage factors in PDOF?
Frontal damage: frame rail shifts. Crush depth
Side damage: side damage widths
