1. Technology of Safety Chapter 16

2. Vehicle Safety Although there has been a steady increase in the number of vehicle accidents per year, car safety has increased Researchers have examined accident reports and have identified safety needs Usually, every part of the car is engineered with safety in mind…

3. How safety features work Recall that that during an accident, when one object hits another, the momentum and the force of the heavier object is transferred to the lighter object so…. Safety features are usually formed to slow down the collision so that the people inside the vehicle experience less force, and thus fewer injuries Crash Test Dummies are real life dolls that are usually used to determine what will happen to people during a collision

4. What can Crash Test Dummies help us with? 1) Help determine how well crumple zones in cars work: Crumple zones are areas of the car that are easily crushed during impact. These are the crushable metal or fiberglass parts found on the exterior of the car, such as the front hood, doors, and trunk. These crumple zones help slow down the collision, reduce force experienced by the occupants and increase the time collision between occupants and the interior of the car. See pg. 289 for a visual of the crumple zone on a small car

5. Continued… 2) Restraining features: These are what hold occupants in place during collisions and prevent them from hitting the dashboard, windshield, sides, roof, etc. They also help someone from being tossed out of a car. These are things like, seatbelts, air bags, headrests, child seats, etc. 3) Operational Features: These are things that operate all of the time to keep you safe, such things as: mirrors, headlights, turn signals, brakes, etc. 4) Structural Features: External features of the car that increase safety 2 types: rigid and crumple zones Rigid zone- heavy frame, roll bars, roll cage, these prvent crumpling. Crumple zones- usually crush in accidents

6. Road Safety Features There are many features of road s that help reduce the force of a collisions by slowing the impulse, they are: 1) Crash Cushions: usually barrals of water, sand, or foam padding that crush or burst on impact 2) Guardrails: bend (but not break) on impact, these also prevent cars from rolling over or rebounding back into traffic

7. Seat Belts- “Buckle up, it’s the LAW” An ideal seatbelt is SAFE and COMFORTABLE The original seat belts were 2-point belts or lap belts These held people across the pelvis, but did not stop the upper body from moving Today we use 3-point belts or shoulder harness belts These hold the entire body intact, especially the upper body Currently there is no seat belt that holds the head in place, but the head rest does an ‘alright’ job.

8. How does a seat belt work? There are 2 main areas of a seat belt 1) Webbing: seat belts are made up of nylon or polyester that can stretch ever so slightly without breaking, this allows the passenger to stop more gradually 2) Retractor Unit: A pendulum and ratchet maintains tension on the webbing when the vehicle comes to a quick stop

9. Child restraints The Canadian Automobile Association reports that up to one third of Canadian children are not properly restrained There are many types of car seats, but for the most part it is recommended that baby seats go in the back of the car, and or turned around to help prevent the baby’s head from hitting the dashboard or something hard -see pg. 297 for different types of baby car seats

10. Air bags Air bags are rolled up in the steering wheel and in the passenger-side dashboard. Air bags decrease the velocity and momentum of your head moving forward after a collision During a collision a chemical reaction inside the air bag causes it to inflate with Nitrogen gas in less 30 milliseconds. New wave, the 3 rd Generation air bags now can detect mass of the occupants and adjust the force of the air bag accordingly, some air bags can be turned on and off. New air bags act like a catchers mitt and cradle a body that is thrown against them