1. COLLISION INVESTIGATION
SEATBELTS, SPEED
&
COLLISION INVESTIGATION
Presenter:
Powerpoint Templates

2. News Bulletin Seatbelts Save Lives!
With tongue firmly planted in cheek – this slide is not news to anyone.
Seatbelts Save Lives!

3. Seatbelts save how many lives in Canada each year?
Question 1
Seatbelts save how many lives in Canada each year?
Ask the following three questions to establish the effectiveness of seatbelts in reducing death and injury. (Each line appears on a click)
Question 1:
Seatbelts save how many lives in Canada each year?
1000
1000!

4. Question 2
Seatbelts increase your chances of surviving a collision by ___%?
Question 2:
Seatbelts increase your chances of surviving a collision by ___%.
Almost 50%
Almost 50%

5. Question 3
What percentage of drivers and passengers killed in collisions were not wearing a seatbelt at the time of the crash?
Question 3
What percentage of drivers and passengers killed in collisions were not wearing a seatbelt at the time of the crash?
Almost 40%
Almost 40%

6. What happens to you during a crash?
Think about:
When the car stops suddenly.
If you didn’t have a seatbelt on.
The speed of vehicle before the crash.
Momentum – amount of motion (momentum (p) = mass x velocity)
Car stops suddenly but you are still moving. Consider the forces on your body from the momentum.
If you don’t have a seatbelt on you will knock around the car/truck or be ejected.
The faster the car is going the greater the forces - greater distances travelled inside or outside the car.

7. So Are You In or Are You Out?
You are travelling at 56 km/hr.
You hit something and are not wearing your seatbelt
F = ___________lbs x
(force) your body weight (deceleration of vehicle,
roadway friction and gravity)
So at 56 km/hr on impact, the force (F) exerted on your body is ___________ lbs
It is your seatbelt that holds you in
Example of the forces that are exerted on your body – even in a slow speed crash. Participants likely have a cell phone that has a calculator for figuring out this equation.
Examples:
120 lb driver/passenger = lbs of force.
150 lb driver/passenger = lbs of force.
200 lb driver/passenger = lbs of force.

8. Engineered Life Space
Vehicles are designed with an engineered life space which can withstand the force of most impacts
Vehicles are designed with an engineered life space, which can withstand the force of most impacts.

9. Point out the area of the passenger compartment or engineered life space.
Vehicles are designed with crumple zones to absorb the energy of impact in a crash and therefore reduce the impact on the people in the vehicle.

10. Engineered Life Space
Seatbelts keep drivers and passengers in this space where they are safest
Over the next few slides emphasize the importance of the seatbelt in keeping the people in the vehicle from flying around or being ejected.

11. Life Space
Point out the engineered lifespace remaining in these crashes.
Life Space

12. Life Space
Even large commercial vehicles are designed to maintain the engineered life space. Here, this semi rear-ended a gravel truck. Note how the engine was driven back and down under the cab.

13. Life Space
This car was severely damaged on the driver’s side causing the vehicle to enter the ditch and roll.
The roof is reinforced to take reasonable crushing forces in the event of rollover, again protecting the engineered life space.

14. The Engineered Life Space is where you want to stay in a crash.
How? – by wearing a seatbelt properly.
Life Space

15. How does speed affect your driving?
Ask for examples of how speed can affect your driving ability or car’s performance.

16. How does speed affect your driving?
The faster you drive:
the longer it takes to stop
the harder you hit
the more damage to you and the vehicle
Driving a few km/hr over the posted speed limit:
Reduces your ability to steer safely around curves or objects on the road
Decreases your field of vision and your peripheral vision
Extends the distance required to stop your vehicle in emergency situations
Reduces your ability to obey traffic control devices such as red lights and stops signs
Increases the chances that you will lose control of your vehicle
Reduces the effectiveness of seatbelts and other safety devices such as airbags and side impact beams
Increases probability of death or injury if there is a crash
Reduces the effectiveness of roadside hardware such as barriers, crash cushions and bridge rails

17. Speed
When damage exceeds the vehicle design, the engineered life space is minimal = a fatal collision
There is a point where the engineered life space will not survive the speed/force created by the crash. When the engineered life space fails the crash can be fatal.

18. Investigate stopping distances at different speeds. Questions:
Questions:
Did you realize how much difference a few kms/hr make in stopping distances?
Why are playground zones posted at 30 km/hr?
What happens when it is raining/snowing?
A Canadian football field is 100m long.
ICBC – Speed – fast facts LP73 (052009)

19. REACTION TIME AND STOPPING DISTANCE CHART
REACTION TIME AND STOPPING DISTANCE CHART * Please note that this chart is based on pavement driving and “normal” conditions..
DECIDE
To STOP
10 m
20 m
30 m
40 m
50 m
60 m
70 m
80 m
90 m
80 km/h
REACTION: 22 m
STOPPING DISTANCE: 34 m
85 km/h
REACTION: 24 m
STOPPING DISTANCE: 38 m
90 km/h
REACTION: 25 m
STOPPING DISTANCE: 43 m
100 km/h
REACTION: 28 m
STOPPING DISTANCE: 47 m
SPEED OF IMPACT
44 km/h
Optional slide to show potential crash as different speeds.
A crash at 100 km/hr is survivable. A crash at 120 km/hr is probably fatal!
110 km/h
REACTION:
31 m
STOPPING DISTANCE: 63 m
SPEED OF IMPACT
77 km/h
120 km/h
REACTION: 33 m
STOPPING DISTANCE: 76 m
SPEED OF IMPACT
96 km/h -
FATAL
* vehicle shown in proportion to actual stopping distances
CoastRange driver training program and workbook

20. Activity
Collision Reconstruction

21. Collision Reconstruction
Collision Scene Investigators
(C.S.I.)

22. Steps to collision reconstruction
Identify all evidence;
Analyze damage profiles of involved vehicles;
Follow the evidence from the vehicles to find the area of impact;
Determine approach of each vehicle based on your findings.
If you arrived on the scene as the collision investigator, what would you observe on arrival?
Observations could include:
Road conditions (wet, dry, icy, snow covered, bumpy, washboard, is it gravel, asphalt, etc)
Environmental conditions (sunny, raining, snowing, foggy, blowing snow)
Time of day (day or night, dusk or dawn, sun position on the horizon) 
Damages to each of the vehicles;
Scrapes, gouges, debris, fluid trails

23. The Dispatch Two (2) vehicle collision One confirmed fatality
East-west stretch of highway
Stress that this is actually all the information that is obtained in some cases. All the information required to complete the investigation is obtained at the scene.

24. Your collision scene This is what you find when you arrive on scene:
-The blue and green lines represent fluid trails from the vehicles;
-The black lines are tire marks from the vehicles.
Step 1: Mark these lines using your dry erase markers on your laminated intersection card.
Important information to note:
Where the vehicles ended up;
Where the roadway evidence begins.
Step 2: Place the toy cars on your intersection where the vehicles ended up.

25. Vehicle #1
Pay close attention to the damage on vehicle #1. Use this information to help determine where you think the vehicle was on the roadway before the crash occurred.
Step 3: Place sticker dots on toy car #1 where damage occurred due to impact.
Note: The Fire Department cut the “b” pillar off and removed both the driver’s door and the driver’s rear door to assist in extrication of the driver.
The “b” pillar is the structural support that the door would latch to. The “a” pillar is the support that the windshield is attached to and the “c” pillar is where the back window is attached.

26. Vehicle #2
Imagine what it would take to produce the damage to this vehicle by matching it with the damage from the other vehicle.
Step 4: Place sticker dots on toy car #2 where damage occurred due to impact.
Use the toy cars and position them in various locations to simulate how the damages would occur.
Keep in mind that some of the damages to the vehicles are caused by the Emergency Services extricating injured people from the vehicles (note the driver’s door is opened, and the passenger door is bent downward).
Step 5: Place both toy cars on the intersection where you think they were traveling from before the crash. Which lanes? Which directions were they traveling?

27. The Scene V2 V1 Looking north west Looking west Looking east
Step 6: Make sure that the road evidence from the photos matches the evidence you’ve drawn on your laminated intersection. Add any pieces that may have been missing.
Looking east
Looking north west

28. Hints
Think physics…throw two die-cast cars together and see where they end up.
Look at the fluid spray and final rest of the vehicle to see where they started.
Try to align the damage on each vehicle.
Try different ideas and see which one makes the most sense given the evidence.
Then determine which vehicle was at fault.ult.
Step 7: Try different scenes and see what the evidence supports. Physically push the toy cars into each other to see where they end up.
Step 8: Reach consensus in your group. What is your conclusion? What happened?
Have each group present their findings back to the class including direction each vehicle was traveling, were the vehicles traveling at the same speed, and cause of the crash.
When each group has presented their findings, work together as a class to come up with one common conclusion as to how the crash occurred.

29. SPOILER ALERT!
The next slide shows the ANSWER!

30. The Actual Reconstruction
It was determined in this investigation the north bound white truck failed to stop at the stop sign and struck the west bound grey truck. Both vehicles then traveled north-west post collision coming to rest in the north west ditch.
The vehicle speeds were calculated using the Conservation of Linear Momentum by carefully obtaining the approach and departure angles combined with the mass of each of the vehicles combined with the occupant weights. The white truck (north bound) was calculated at 100 km/hr and the grey truck (west bound) calculated at 114 km/hr. The white truck failed to stop at the stop sign.
Discussion notes for incorrect findings:
Had the white truck stopped or even yielded, they would not have reached a speed of 100 km/hr by the site of the crash.
If the white truck had stopped and then proceeded through the intersection when it was unsafe to do so (i.e. they didn’t see the oncoming grey truck), both vehicles would have ended up in the south-west ditch due to the laws of physics.
Combine this data with the rest of the evidence that you collected from examining the photographs. Could this collision have been avoided?
Now as a group discuss possibilities as to why the collision occurred. (cell phone use, texting, talking with a passenger, reaching for something, sun position, playing with the stereo, adjusting the GPS, etc.)
All of these factors are decisions people make. This is why a collision is rarely ever classified as an accident, because these crashes are preventable. Accidents cannot be prevented.