The use of the R2 coefficient of determination to determine the impact of selected parameters on the number of fatalities in road accidents in Poland compared to selected European countries in 2010-2020

The article presents statistical data on the state of road transport safety in Poland against the background of selected European countries in the years 2010-2020. The article presents the characteristics of the change in the length of motorways along with the percentage rate of increase in the length of motorways in selected European countries. Statistical data on the number of registered motor vehicles in Poland against the background of selected European countries in the analyzed period are presented. The main purpose of the article is to use the coefficient of determination R2 to determine the impact of the number of registered motor vehicles and the length of motorways on the number of fatalities in road accidents in selected European countries. The authors chose the coefficient of determination R2 as an indicator of how reducing the overall number of road accidents and increasing the length of motorways will affect the number of fatalities. The coefficient of determination is used to determine what percentage of one variable affects the variability of the other variable. The determined high value of the determination index R2 (close to 1) indicates a large impact of the analyzed variable on the number of fatalities in road accidents. The high result of the determination coefficient R2 for Poland in terms of the analyzed variables confirms that a further reduction in the number of fatalities in road accidents is possible thanks to the expansion of motorways and the reduction of the number of motor vehicles.