## 7 Conclusions  
In this paper, we investigated the comparative differences in fundamental traffic flow relations present under continuous and interrupted traffic stream characteristics on the two selected segments of regional road ZC5210 in the Republic of Croatia to identify the specific functional forms of \"speed-density\" and \"flow-density\" fundamental diagrams suitable for modeling continuous and interrupted traffic stream conditions. The results and conclusions derived from this research can be summarized as follows:  
* Based on the comparative analysis of R-squared values determined for the twelve traffic flow models considered fitted to empirical data collected under continuous and interrupted traffic stream conditions, it is revealed that [PERSON]'s five-parameter sigmoid model best fits the empirical data, with [PERSON]'s correlation coefficient of 0.6191 and coefficient of determination of 0.3833. * The results obtained indicate that the practical road capacity value representative of continuous and interrupted traffic stream conditions varies significantly depending on the selected model and prevailing traffic stream conditions. The practical capacity of the observed regional road, determined by twelve calibrated traffic flow models, ranges from 1084 to 2333 veh/h/lane under continuous and from 799 to 1793 veh/h/lane under interrupted traffic stream conditions. Depending on the traffic flow model considered, the practical road capacity under interrupted traffic stream conditions is 5-46.4% lower than under continuous traffic stream conditions, while the relative difference in free-flow speed values representative of modeling traffic flow characteristics under continuous and interrupted traffic stream conditions can reach up to 41.3%. * The practical capacity of the observed regional road is reached at significantly different levels of traffic density when comparing continuous and interrupted traffic stream conditions. Depending on the selected model, the saturation traffic flow density value for continuous traffic flow conditions ranges between 40 and 117 veh/km/lane, while in interrupted traffic flow conditions, it ranges between 37 and 129 veh/km. \begin{table}
\begin{tabular}{l c c c c} \hline \hline
**Traffic Flow Parameter** & \(t\)**-Statistic** & \
\begin{tabular}{c} **Critical** \\ **\(t\)-Value** \\ \end{tabular} &
\begin{tabular}{c} **95\%** \\ **Confidence Interval** \\ \end{tabular} & **Hypothesis (H1)** \\ \hline Mean vehicle speed (V) & 34.6934 & 1.96 & [17.9685, 20.1221] & Accepted \\ Mean vehicle flow (q) & 5.04610 & 1.96 & [71.3028, 161.9837] & Accepted \\ Mean traffic density (g) & 26.6395 & 1.96 & [\(-\)20.6768, \(-\)17.8408] & Accepted \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Comparative summary of \(t\)-test results for significance of the differences in empirical values of the main traffic flow parameters determined in continuous and interrupted traffic flow conditions on the observed road sections of regional road ZC5210. Source: Created by authors. * The statistical significance of the differences in mean speed, mean hourly vehicle flow and mean traffic flow density values determined for continuous and interrupted traffic flow conditions by the proposed \"speed-density\" and \"flow-density\" models is confirmed by the _t_-tests conducted. * We reject the Null Hypothesis (H0) and confirm the Alternative Hypothesis (H1) that there is a statistically significant difference in the speed-density and flow-density functional relationships obtained for continuous and periodically interrupted traffic flow conditions on the representative road segments of the selected regional road, and therefore, we conclude that two alternative mathematical formulations of the \"speed-density\" and \"flow-density\" models need to be used to separately model the traffic flow characteristics present under continuous and interrupted traffic stream conditions.