Investigating factors affecting the safety of the Shahrood – Azadshahr transportation system

Road transportation safety is one of the principles of traffic engineering, which in developed countries along with the development of other traffic engineering sectors, the issue of transportation safety has also been taken into consideration. Conducting necessary studies and preparations are tried to minimize accidents and their consequences as much as possible. In this research, various influencing factors on the safety of Shahrood-Azadshahr transportation axis located in Semnan province for the years 2017 to 2019 were investigated. With the help of Minitab statistical software, factors of geometrical parameters of accidents, age of people, education of accident victims and seasons of accidents were investigated. Also, with the help of Easyfit software, the best statistical distribution of accident data in the years 2017 to 2018 was examined. Next, with the help of MLP model, the accidents of this axis were modeled. The results showed that among the factors of geometric parameters, poor pavement is the main cause of accidents in this axis. Also, the most accidents happened to drivers who were between the ages of 31 and 40. Also, drivers who have a diploma have experienced the most accidents. The MLP model had a relatively good performance in modeling, and in the testing stage, the values of R2, MAE and RMSE were 0.84, 1.91 and 2.65, respectively. The results of goodness-of-fit test showed that the Generalized Pareto distribution for the axis of 1397 and 1399 and the Exponential distribution for the Shahrood-Azadshahr axis of 1398 had the best results. Finally, the field visit of this axis showed that there are many problems and shortcomings that need to be fixed.