## 3 Results
### Research Questions' Answers
#### 3.2.8 RQ7  
What Types of Models Were Used for Modeling the Traffic Situation in Flooding? Traffic situations in the event of flooding are typically modeled in the literature using three primary methods: macroscopic, microscopic, and mesoscopic. A combination of these models can also be utilized. Macroscopic traffic modeling, a common approach in this field, is capable of representing congestion or diversion in a large area but cannot represent individual vehicles or people on the network. Many articles [18; 22; 25; 27; 29; 32; 35; 38; 45; 49; 53; 58; 59] used macrosimulation in their methods; however, it cannot properly address the dynamics of the transportation system during a flooding event. Nevertheless, the macroscopic modeling method has advanced in the field of traffic flow theory and control in the form of \begin{table}
\begin{tabular}{c c c} \hline \hline
**Transportation Type** & **Analyzed Traffic Aspect** & **Number of Articles** \\ \hline \hline  & Travel time & 17 \\ \cline{2-3}  & Streets speed & 11 \\ \cline{2-3}  & Travel distance & 9 \\ \cline{2-3}  & Accessibility & 5 \\ \cline{2-3} Private vehicles & Detoured trips & 5 \\ \cline{2-3}  & Lost trips & 3 \\ \cline{2-3}  & Affected population & 1 \\ \cline{2-3}  & Fuel consumption & 1 \\ \cline{2-3}  & Pollution level & 1 \\ \hline \hline  & Access time & 3 \\ \cline{2-3} Emergency vehicles & Service area coverage & 3 \\ \hline \hline  & Number of interrupted trains & 2 \\ \cline{2-3} Public vehicles & Trains interruption duration & 1 \\ \hline \hline  & & \\ \end{tabular}
\end{table} 
Table 4: Number of articles considering the analyzed traffic aspect. macroscopic fundamental diagrams (MFDs), which have been utilized by [PERSON] et al. [29] and [PERSON] et al. [52]. In contrast, microsimulation is a modeling approach that tracks individual vehicles on the network in small time steps, providing very precise results. Despite the higher computational cost and the level of detail required regarding input data, microsimulation is frequently used to analyze the indirect impacts of flooding on transportation. It should be noted that most of the articles that used microsimulation focused on transportation networks in major metropolises of developed countries with a relatively well-recorded database [33; 34; 36; 39; 40; 51; 54; 60]. In addition to the macroscopic and microscopic traffic models, mesoscopic simulation and combined models have received attention in most recent articles. In order to apply the temporal and spatial variation of traffic during flood, the mesoscopic simulation can compute vehicle movements with queues which may run up to 100 times faster than a microscopic model [61]. Thereby, a mesoscopic simulation, which falls between these two modeling approaches, can portray a feasible alternative for the assessment of flood impacts in transportation networks; this method was used by [PERSON] et al. [30]. Additionally, a number of articles used the mesoscopic method in order to make a comparison between their function and results. For example, [PERSON] et al. [52] compared macroscopic and mesoscopic models in their research while [PERSON] et al. [4] applied microscopic and mesoscopic methods for simulating Bristol and Barcelona Road networks. Combined models have been developed by integrating different traffic flow models, such as micro with macroscopic models, and micro with mesoscopic models [62; 63]. The aim of such integration is to obtain a comprehensive understanding of network properties at different levels of complexity. For example, macroscopic modeling is more appropriate for a simplified node representation, while microscopic modeling is better suited to capture vehicle interactions and drivers' mutual influences along links. Although the combined method has been proposed to address these issues, only one article [64] in the current systematic literature review was found to have used this approach in traffic simulation. [PERSON] et al. [47] used a different approach compared to the previously mentioned combined models.