## 2 Research Design and Methods
### The Calculation of Permissible Intensities on the Internal Circuit  
The permissible traffic flow intensity \(\rm I_{P}\) of the overall urban roads is calculated according to the relation (1) [65]:  
\[\rm I_{P}=I_{z}\cdot k_{k}\cdot k_{s}\cdot k_{m}\cdot k_{b}\ [vehicle/h] \tag{1}\]  
where  
\(\rm I_{P}\): permissible traffic flow [vehicle/h];  
\(\rm I_{z}\): the basic value of the permissible traffic flow intensity [vehicle/h];  
\(\rm k_{k}\): coefficient of influence of a light-controlled junction [-];  
\(\rm k_{s}\): width factor [-];  
\(\rm k_{m}\): maneuvering factor [-];  
\(\rm k_{b}\): factor of very slow vehicle [-]. The basic values of the permissible traffic flow intensity \(\rm I_{z}\) depend on the required speed, the proportion of slow vehicles and the longitudinal angle of the road. For a two-lane road, the values of \(\rm I_{z}\) are in Table 1, for a four-lane road in Table 2 [65]. \begin{table}
\begin{tabular}{c c c c c c c c c c c c c c c c} \hline \hline \multicolumn{1}{c}{**Longitudinal Angle [\%]**} & \multicolumn{10}{c}{**Required Speed [km/h]**} \\ \hline \multirow{3}{*}{**+**} & \multirow{3}{*}{**–**} & \multirow{3}{*}{**Length of the Angle Slope [m]**} & \multicolumn{1}{c}{\multirow{3}{*}{**150**}} & \multicolumn{1}{c}{\multirow{3}{*}{**150**}} & \multicolumn{1}{c}{\multirow{3}{*}{**150**}} & \multicolumn{1}{c}{\multirow{3}{*}{**150**}} & \multicolumn{1}{c}{\multirow{3}{*}{**150**}} & \multicolumn{1}{c}{\multirow{3}{*}{**150**}} & \multicolumn{1}{c}{\multirow{3}{*}{**150**}} & \multicolumn{1}{c}{\multirow{3}{*}{**150**}} & \multicolumn{1}{c}{\multirow{3}{*}{**150**}} & \multicolumn{1}{c}{\multirow{3}{*}{**150**}} \\ \cline{3-3} \cline{8-15}  & & & **1250** & & & & & & & & & & & & & & \\ \hline \multirow{3}{*}{3} & \multirow{3}{*}{7} & 250 & 1250 & 1150 & 1000 & 850 & 1450 & 1350 & 1200 & 1000 & 1650 & 1500 & 1350 & 1150 \\  & & 500 & 1250 & 1150 & 1000 & 850 & 1450 & 1350 & 1200 & 1000 & 1650 & 1500 & 1350 & 1150 \\  & & 1000 & 1200 & 1100 & 1000 & 800 & 1450 & 1350 & 1200 & 1000 & 1650 & 1500 & 1350 & 1150 \\  & & 1500 & 1150 & 1000 & 850 & 650 & 1400 & 1250 & 1100 & 900 & 1550 & 1400 & 1250 & 1000 \\ \hline \multirow{3}{*}{5} & \multirow{3}{*}{not applicable} & 250 & 1250 & 1150 & 1000 & 850 & 1450 & 1350 & 1200 & 1000 & 1650 & 1500 & 1350 & 1150 \\  & & 500 & 1250 & 1150 & 1000 & 850 & 1450 & 1350 & 1200 & 1000 & 1650 & 1500 & 1350 & 1150 \\  & & 1000 & 1200 & 1050 & 900 & 700 & 1400 & 1250 & 1100 & 900 & 1650 & 1500 & 1350 & 1150 \\  & & 1500 & 1050 & 900 & 700 & 450 & 1300 & 1150 & 950 & 700 & 1500 & 1350 & 200 & 950 \\ \hline \multirow{3}{*}{7} & \multirow{3}{*}{not applicable} & 100 & 1250 & 1150 & 1000 & 850 & 1450 & 1350 & 1200 & 1000 & 1650 & 1500 & 350 & 150 \\  & & 250 & 1200 & 1100 & 950 & 800 & 1450 & 1250 & 1050 & 900 & 1650 & 1500 & 350 & 150 \\  & & 500 & 1150 & 1000 & 850 & 600 & 1350 & 1200 & 1000 & 750 & 1600 & 1450 & 1300 & 1050 \\  & & 1000 & 900 & 750 & 550 & 300 & 1150 & 950 & 750 & 450 & 1550 & 1400 & 200 & 900 & 650 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Basic values of permissible traffic flow intensities \(\rm I_{z}\) on double-lane urban road [vehicle/h] [65].