This paper is essentially aimed to analyse the influence of human factor in the contest of preventing the accidents.

In addition to that in this paper has also taken into consideration the possibility to give appropriate instruction in order to improve the road safety.

After a short analysis of the general problem conceming the safety both active and passive ones, we have concentrated our attention on the specific area of the physical capabilities of the driver for the control of the vehicle over all the time.

Therefore the biomechanics of the human body has been discussed and analysed in the most important functions of the body which are particularly involved in the vehicle's management.

The reducedc apabilities of the driver is a consequence of the stress which is related not only to the time involved but essentially to the environment including also the interface between the driver and the structure of the vehicle, such as the seat and the angle of visibility.

Incorrect physiological posture of the driver or inadequacy of the structure, will stress or pain during the driving time with a consequence of reducing the capabilities for the vehicle's control. Obviously this situation will increase the probabilities of crashes and accidents.

The areas of the human body particularly involved for stressing the driver, are the two parts of the spine which have more possibilities of movements:​ these are the cervical and lumbar ones.

In order to give the possibilities of analysing as deeply as possible the problem, an appropriate appendix has been prepared for discussing mathematical and analytical methodsf or calculating forces, stresses and displacement of the most significant vertebras.

As a conclusion of this paper the real possibilities of the driver to keep the control ofthe vehicle at a sufficient level can be envisaged