CAR SAFETYActive and Passive:Car safety features are
CAR SAFETYActive and Passive:Car safety features are grouped into two categories: Active and Passive. Active feature are designed to reduce the likelihood of a crash.
Things such as tires, brakes, lights and steering are active features. The most important of all of them however is the driver.Passive safety features aim to reduce the damage done to a car’s occupants in the event of a crash.
These include things like seatbelts, airbags, and crumple zones.For all these features any car can still crash so this report aims to make you more aware of the safety aspects of modern cars and what role they play in driving.Active Safety FeaturesBrakes:The brakes play one of the most important roles in overall safety and so it important that they are reliable and durable.A good braking system always stops the car in the minimum distance possible while remaining stable, have a constant response which is consistent with brake pedal pressure and let you easily control the car while braking.
Disk and drum brakes are the two types used in cars. Drum brakes are very good to have on your rear axel but not as effective on the front where better balance and heat dissipation is a must.Heat dissipation is the brakes ability to get rid of the immense amount of heat created by the friction between the brake surface and frictional pads. This is very important since it reduces the amount of friction that can be applied (brake fade) and it can boil the brake fluid rendering the brakes completely useless.Disk brakes can dissipate heat much more effectively and therefore are much better when you brake often or at high speeds. The best disk brakes are ventilated.
ABS:ABS (Anti-lock Braking System) is a system which stops the wheels locking up into a skid when braking on slippery surfaces. It works by using a computer which monitors wheel speeds and drives pistons which alternatively increases and decrease brake pressure several time a second on individual wheels when it senses they are about to lock up.Preventing skidding during braking increases the drivers control of the car and greatly reduces the chance of a crash.Stability and Handling:A car with good handling and stability is much safer to drive than a poorly designed one. This is because it grips better and is more responsive.
Good stability and handling is achieved with a combination of suspension, steering, acceleration, brakes and weight distribution. Each car manufacturer has its own way of increasing its car’s performance.Other Minor Features:Many things that people take for granted in cars are really safety features designed to stop crashes from occurring.Lights increase visibility and make it easier for other vehicles to see you, mirrors demisters and wipers also help you see hazards earlier and horns and reversing beepers warn others to move.Also comfort features such as adjustable seats and steering columns, air con, and heating help reduce driver fatigue and increase control over the car.Passive Safety FeaturesCrumple Zones:The front and rear of most modern cars are designed to crumple progressively absorb some of the force of a crash and slow the car more gently. Since slower deceleration reduces the force on the occupants this reduces the chance of injury.
Roll Cages:The passenger compartment itself is built to withstand the force of a car rolling to stop the roof crushing the passengers and so the sides and floor of the car don’t close in during a crash. The roll cage also has barriers to stop the engine, bonnet or wheels intruding into the passenger compartment.Locks and hinges on the doors are also designed not to fail under the stress of a crash to prevent occupants being thrown clear of the car.Airbags:Frontal airbags are stored in the steering wheel for the driver and the dash board for the passenger. They are designed to inflate almost instantly during a crash and work in conjunction with a seatbelt to restrain your forward motion and stop you hitting your head and chest on the steering wheel, dash or windscreen.
Although airbags are a valuable safety asset they also have the potential to cause injury because of the incredible speed they deploy. An airbag is designed to inflate, stop the impact of the passenger and deflate in less than a tenth of a second. That means it will deploy towards you at somewhere between 160 and 320km/h. Since airbags deploy at such a high speed it can be dangerous to sit too close to the steering wheel and you should never have anything between you and the airbag or place a child seat in the front.Some newer cars are now equipped also with side airbags these deploy from the seats, doors and pillars to stop your head and torso impacting with the side of the car in a offset crash.Car Size:Although the size of a car isn’t really a safety feature it does play a part in crash safety. Larger cars will protect you much better in a crash due to bigger crumple zones.
In single car crashes the fatality rate in nearly four times a high in small cars compared to large ones.Seatbelts:Seat belts work in many ways to reduce the likelihood of injury in a crash. They are designed to be worn with no slack and lock into place when there is a sudden pull on them. In almost any type of crash a seatbelt protects you from injury by preventing a second impact.’ That is they stop you from colliding with the cars interior or other passengers. Seatbelts are the number one life saver in car crashes and therefore it is mandatory to where one whenever traveling in a car.
Seats and Headrests:Seats in cars are designed to withstand the force of a crash and be securely attached to the floor. Newer cars have anti-submarining’ front seats designed to stop you sliding under the seatbelt. Since seats are the only thing between the front passengers and the rear passengers they are also designed to stop injury to the front occupants from impact from the rear as well as have deformable crossbars and lots of padding to act similar as an airbag for the rear passengers.Headrests play an important role in rear impact crashes.
They greatly reduce the chances of whiplash by halting the motion of the head before it strains the neck.Headrests should be positioned at the head’s centre of gravity and as close to the back of the head as possible.BibliographyCar Safety: what to look for and how it works: http://www.ltsa.govt.nz/factsheets/72.html