Background: About 1.35 million people died in traffic accidents around the world in 2018, make this type of
accidents the 8th cause of death in the world. Particularly, in Spain, there were 204,596 traffic accidents during 2016
and 2017, out of which 349,810 drivers were injured. The objective of this study was to understand to what extent
seat belt non-use and human factors contribute to drivers injury severity.
Methodology: The results are based on the information and 2016–17 data provided by the Spain national traffic
department “Dirección General de Tráfico” (DGT). The discretization model and Bayesian Networks were developed
based on important variables from the literature. These variables were classified as; human factor, demographic
factor, conditioning factor and seat belt use.
Results: The results showed that failure to wear the seat belt by drivers are likely to increase the risk of fatal and
sever injury significantly. Moreover, distraction and road type road can contribute to the accident severity.
