Every day millions of people use different means of transport, whose number has been increasing exponentially as well as their performances along last decades due to technological developments.
This fact has risen the accident rate and made transport safety of capital importance. For this reason, in the last years, considerable investments have been carried out by companies, governments and associations in educational advertising campaigns and researches to design safer vehicles and infrastructures with better performances.
Thanks to advances in computer technology, there has been a significant improvement during the design phase since virtual simulations have reduced the cost and the time needed for any modification. Consequently, new design
Moreover this increment, there has been a change in the type of vehicles, their characteristics (speed, mass and size) and performances, that are running on the roads nowadays. As a consequence of this evolution, a notable increase of accident rates occurred and it became an important problem for society, in order to solving it, governments decided to react writing laws and decrees, setting higher standards for vehicles and road restraint systems and doing awareness campaigns sponsoring a responsible behavior while
In fact, road accidents may occasion many social costs, such as injured people that are disabled for life by road traffic crashes, families with heavy burdens, psychological problems or loss of labor productivity. The most productive age group, those aged between 15 and 44 years, is heavily represented in road traffic injuries; the economic impacts of injuries in this age group are therefore especially damaging [5].
Furthermore, it is not just the social cost that road traffic accidents cause, there is also an economical cost that must be taken into account. In 2000, as part of the review undertaken by the United Kingdom-based TRL Ltd on the number of road traffic collisions globally, information on road crash costs from 21 developed and develop¬ing countries was analyzed. This study found (as it is showed in Table 2.1) that the average annual cost of road crashes was about 1% of GNP in developing countries, 1.5% in countries in economic transition and 2% in highly-motorized countries. According to this study, the annual burden of economic costs glo¬bally is estimated at around US$ 518 billion [5]