# Beyond Static Estimates: Dynamic Simulation of Fire-Evacuation Interaction in Historical Districts
## 3 Results
### Evacuations in Historical District
#### 3.4.2 Congestions  
Congestion occurs under both of the most unfavorable scenarios, primarily within the first 25 min. Given that the development and impact range of the fire remain limited during this period, these congestion points are identified as the primary factors contributing to detours and deceleration, which consequently increase evacuation duration. Both the 2-600 and 16-600 scenarios report an equal number of congestion points, totaling 14 each.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Criteria**} & \multicolumn{3}{c}{**Inside Historical District**} & \multicolumn{3}{c}{**Outside Historical District**} \\ \cline{2-7}  & **2-600** & **16-600** & **Static** & **2-600** & **16-600** & **Static** \\ \hline Minimum Evacuation & 1.01 & 5.36 & 3.59 & 296.41 & 299.93 & 290.39 \\ Distance (m) & 685.16 & 556.98 & 551.69 & 702.58 & 891.32 & 687.15 \\ Average Evacuation Distance (m) & 264.36 & 260.2 & 209.4 & 469.51 & 446.16 & 443.96 \\ Evacuation & \(\leq\)100 m & 18.33 & 12.16 & 12.36 & 0.00 & 0.00 & 0.00 \\ Distance & 100–300 m & 39.90 & 39.69 & 40.15 & 33.96 & 33.22 & 33.14 \\ Percentage & 300–500 m & 40.86 & 47.50 & 46.82 & 44.36 & 43.54 & 44.05 \\ (\%) & \(>\)500 m & 0.91 & 0.65 & 0.67 & 21.68 & 23.25 & 22.81 \\ Minimum Evacuation & 9 & 7 & 4 & 241.94 & 241.94 & 241.94 \\ Duration (s) & 2088 & 1729 & 628 & 1928 & 1875 & 715.79 \\ Average Evacuation & 586.52 & 638.7 & 250 & 692.78 & 641.29 & 359.46 \\ Duration (s) & \(\leq\)200 s & 21.40 & 14.51 & 42.30 & 0.00 & 0.00 & 0.00 \\ Evacuation & 200–400 s & 18.93 & 20.10 & 56.31 & 8.73 & 8.83 & 68.74 \\ Duration & 400–600 s & 15.79 & 17.47 & 1.59 & 19.07 & 20.60 & 30.68 \\ Percentage & 600–800 s & 15.42 & 15.32 & 0.00 & 20.30 & 21.46 & 0.57 \\ (\%) & \(>\)800 s & 28.46 & 32.60 & 0.00 & 51.90 & 49.11 & 0.00 \\ Congestion quantity & 14 & 14 & - & - & - & - \\ Average Distance between & & & & & & \\ zones over 50 \({}^{\circ}\)C to & 169.05 & 308.48 & - & - & - & - \\ Congestions (m) & 7629 & 7881 & 7765 & - & - & - \\ Total evacuees of eastern exits & 2171 & 2189 & 2137 & - & - & - \\ Time of maximum capacity & - & - & - & 16 m 45 s & 13 m 48 s & - \\ \hline \hline \end{tabular}
\end{table}
Table 6: Detailed comparison of the worst scenarios: inside vs. outside the historical district.  
Further analysis indicates that variations in evacuation efficiency and the number of congestion points are observed across different warning distances (Figure 7e). As the warning distance increases, congestion becomes more frequent. As indicated in Figure 8a,b, congestion points are predominantly located along the principal east-west roads, a phenomenon attributed to the elevated road network density and the presence of multiple exits within the district, rendering these roads critical evacuation routes. This suggests that the width of primary evacuation routes, among the built environment factors associated with early congestion, plays a pivotal role, with roads connecting the greatest number of branches being more susceptible to congestion than those representing the shortest paths.  
Beyond their quantity, the spatial distribution of congestion points is of critical importance. In the 2-600 scenario, the average distance between congestion points and high-temperature zones (exceeding 50 \({}^{\circ}\)C) is 169.05 m, compared to 308.48 m in the 16-600 scenario. Congestion in the former scenario poses a greater threat to vulnerable populations and is more likely to necessitate detours, a pattern primarily linked to the eastward wind in Case 16, which causes the fire's development center to shift rapidly away from the ignition point.