## 5 Results  
As a result of the simulation tests, changes in the value of travel costs were determined as a function of the selected input parameters. The values of travel costs were simulated based on literature data [34; 35; 36]. Table 5 shows the results of the experimental tests we carried out. Based on the data from Table 5. as well as Equation (3) for the three input factors, we developed further formulas and charts describing travel costs in the context of the type of vehicle, vehicle maintenance costs, and travel distance. Equation (3) for the three input factors was defined as  
\[f(x_{1},x_{2},x_{3})=k_{0}+k_{1}x_{1}+k_{2}x_{2}+k_{3}x_{3}+k_{11}x_{1}^{2}+k_ {22}x_{2}^{2}+k_{33}x_{3}^{2}+k_{12}x_{1}x_{2}+k_{13}x_{1}x_{3}+k_{23}x_{2}x_{3} \tag{3}\]  
where:  
\(f(x_{1},x_{2},x_{3})\)--results factor;  
\(x_{1},x_{2},x_{3}\)--input parameters; \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & \multicolumn{3}{c}{**Input Factors on the Standard Scale**} & \multicolumn{3}{c}{**Input Factors on the Real Scale**} \\ \cline{2-7}
**Sample No.** & \(x_{1}\) & \(x_{2}\) & \(x_{3}\) & **Type** & **Maintenance** & **Distance** \\  & & & & [USD/km] & **Cost** [USD/km] & **[km]** \\ \hline
1 & \(-1\) & \(-1\) & \(1\) & \(0.311\) & \(0.062\) & \(20,000\) \\
2 & \(1\) & \(-1\) & \(-1\) & \(0.249\) & \(0.062\) & \(10,000\) \\
3 & \(-1\) & \(1\) & \(-1\) & \(0.311\) & \(0.211\) & \(10,000\) \\
4 & \(1\) & \(1\) & \(1\) & \(0.249\) & \(0.211\) & \(20,000\) \\
5 & \(-1\) & \(0\) & \(0\) & \(0.311\) & \(0.124\) & \(15,000\) \\
6 & \(1\) & \(0\) & \(0\) & \(0.249\) & \(0.124\) & \(15,000\) \\
7 & \(0\) & \(-1\) & \(0\) & \(0.233\) & \(0.062\) & \(15,000\) \\
8 & \(0\) & \(1\) & \(0\) & \(0.233\) & \(0.211\) & \(15,000\) \\
9 & \(0\) & \(0\) & \(1\) & \(0.233\) & \(0.124\) & \(20,000\) \\
10 & \(0\) & \(0\) & \(-1\) & \(0.233\) & \(0.124\) & \(10,000\) \\
11 & \(0\) & \(0\) & \(0\) & \(0.233\) & \(0.124\) & \(15,000\) \\ \hline \hline \end{tabular}
\end{table} 
Table 4: The three-input-factor experiment plan used in the research. \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Sample No.**} & \multicolumn{3}{c}{**Input Factors on the Standard Scale**} \\ \cline{2-4}  & \(x_{1}\) & \(x_{2}\) & \(x_{3}\) \\ \hline
1 & \(-1\) & \(-1\) & \(1\) \\
2 & \(1\) & \(-1\) & \(-1\) \\
3 & \(-1\) & \(1\) & \(-1\) \\
4 & \(1\) & \(1\) & \(1\) \\
5 & \(-1\) & \(0\) & \(0\) \\
6 & \(1\) & \(0\) & \(0\) \\
7 & \(0\) & \(-1\) & \(0\) \\
8 & \(0\) & \(1\) & \(0\) \\
9 & \(0\) & \(0\) & \(1\) \\
10 & \(0\) & \(0\) & \(-1\) \\
11 & \(0\) & \(0\) & \(0\) \\ \hline \hline \end{tabular}
\end{table} 
Table 3: The experiment plan for three input factors. Detailed definitions of the individual input parameters:  
\[x_{1}=\left\{ \begin{array}{c}-1\text{ {for individual vehicle}}\\ 0\text{ {for the vehicle from car -- sharing system}}\\ 1\text{ {for the autonomous vehicle}}\end{array} \right.\]  
\[x_{2}=\left\{ \begin{array}{c}1\text{ {for the individual vehicle maintenance costs}}\\ 0\text{ {for the car -- sharing's vehicle maintenance cost}}\\ 1\text{ {for the autonomous vehicle maintenance cost}}\\ \end{array} \right.\]  
\[x_{3}=\left\{ \begin{array}{c}-1\text{ {for }10,000\text{ {km distance}}}\\ 0\text{ {for }15,000\text{ {km distance}}}\\ 1\text{ {for }20,000\text{ {km distance}}}\end{array} \right.\]  
\(b_{0}\), \(b_{1}\), \(b_{2}b_{3}\), \(b_{11}\), \(b_{22}\), \(b_{33}\), \(b_{13}\), \(b_{12}\), \(b_{23}\)--regression coefficients. Details of the simulation values for the total travel cost are shown in Figures 5-13. Figures 5-7 show the impact of vehicle maintenance costs (\(x_{2}\)) and distance (\(x_{3}\)) on the total cost of travel, assuming a constant value for the vehicle type (\(x_{1}\)). It was found that the factors of vehicle maintenance costs and distance had a linear effect on the total cost of travel in all simulated \(x_{1}\) cases. Variation of the vehicle type had the most significant impact on the total cost of travel. Autonomous vehicles showed the most considerable variability (Figure 7).