The Importance Of Automobile Safety

2.2 Automobile safety

Automobile safety may be considered as the design, construction, equipment and regulation of vehicles to minimize the probability and effects of road traffic accidents.

At the beginning of the automobile industry, safety was not a design parameter, nevertheless, its influence has increased along years. An illustrative example about the difference between first cars and modern ones is reported in figure 2.5.

As figure 2.5 shows, old cars did not have mechanisms or systems in order to avoid an accident or protect the occupants and attenuate the impact. This problem has been confronted by new design of cars and it has induced an increment of automobile safety. Depending on the point of view, safety may be classified as active

modern car [10]

2.2.1 Active safety

Active safety is formed by all systems installed in the vehicle whose purpose is to avoid a collision, or at least, to reduce the probability that it occurs.

It includes [11]:

• DADS (Driver Alertness Detection System): System to prevent crashes caused by fatigue.

• Automatic Braking systems: To prevent or reduce the severity of

2.2.2 Passive Safety

“Passive safety, or crashworthiness, is an engineering activity aimed to reduce severity of impacts and risks of injuries to vehicle’s occupants while an accident is occurring” [11].

Impacts are very short periods where highly unstable systems take place. As a result, it is quite difficult to measure all variables involved during the phenomenon.

An important mechanism used in crashworthiness, is controlled deformation of parts of cars so as to absorb the impact energy, then a detailed research of materials and structures must be done.

The main goal, which crashworthy systems should achieve, may be a compromise solution between prevent fire, contain accelerations transferred to the occupants, contain impact velocities of occupants against hard surfaces and preserve living space around the occupant, as small deformations or avoiding external objects intrusion. In order to minimize risks and dangers to the occupants.

It includes [12]:

• Seatbelts: Limit the forward motion of an occupant, stretch to absorb energy, to lengthen the time of the occupant 's negative acceleration in a crash, reducing the loading on the occupants’ body. They prevent occupants being ejected from the vehicle and ensure that they are in the correct position for the operation of the