## 3 Results
### Modeling and Simulation Results
#### 3.4.2 The Effect of Small Groups on Evacuation of MIGs  
As shown in Table 6, compared with scenario 1.0, the scenario 2.0 TET, average OET, and average OTJT of MIGs increase by 145.85%, 33.84%, and 192.48%; average OED and average OES decrease by 8.26% and 28.21%, respectively. As shown in Table 7, the OET of 63.06% of MIGs and the OTJT of 81.98% of MIGs increase, and the OED of 68.47% of MIGs and OES of 88.29% of MIGs decrease. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Exit** & **Scenario 1.0** & **Scenario 2.0** \\ \hline Exit 1 & 90 & 75 \\ Exit 2 & 86 & 102 \\ Exit 3 & 8 & 7 \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Number of occupants arriving at each exit. Figure 14: Evacuation paths. (**a**) Scenario 1.0; (**b**) Scenario 2.0. The distance between MIGs in the same small group affected their assembling behavior and then affected the overall evacuation. Given the limited number of small groups consisting of three and four occupants, our analysis primarily focused on examining the effect of the distance between MIGs within small groups of two occupants on evacuation. Among the 18 small groups of two occupants with non-adjacent members, two failed to gather, because the leader would not be able to stop and wait for followers in such a high-density crowd but would be pushed forward by the crowd. The assembling time of the remaining 16 small groups is shown in Table 9. As shown in Figure 15, the assembling time of MIGs is divided into three stages. From 0 s to 11 s, 9 small groups completed aggregation; 11 s to 38 s, 6 small groups completed the aggregation, the TET of small groups that have completed aggregation within 11 s to 18 s is relatively long, which may because the maximum density of occupants occurred between the two rows of waiting seats in the primary waiting area south (Figure A1(f2)); and the last small group gathered for 121 s.  
According to the scatter plots generated in SPSS (Figure S1), we carried out curve estimation analysis (Table S1). The results of the curve estimation analysis are presented in Table 10, where the spacing of MIGs negatively affect the evacuation of MIGs. Specifically, when the increase in OES served as an independent variable, it exhibited a quadratic correlation with the increase in OET and OED. The other two variables demonstrated linear correlations. A longer distance between MIGs resulted in extended assembling time and increased values for OTJT, OET, and OED. The correlation analysis revealed that the strongest correlation with the distance between MIGs was assembling time, with a correlation coefficient of 0.740, followed by increase in OED with a correlation coefficient of 0.569. The increase in assembling time directly led to higher values for OET and OTJT, with correlation coefficients of 0.683 and 0.589, respectively. Figure 15: Number of small groups of two occupants successfully assembled and their total evacuation time. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Small Group** & **Distance between** & **Assembling Time** & **Small Group** & **Distance between** & **Assembling Time** \\
**Number** & **MIGs (m)** & **(s)** & **Number** & **MIGs (m)** & **(s)** \\ \hline
1 & 12.15 & 0.9 & 9 & 81.13 & 10.8 \\
2 & 10.57 & 0.9 & 10 & 124.51 & 17.3 \\
3 & 12.24 & 1 & 11 & 50.26 & 18.5 \\
4 & 18.88 & 1.4 & 12 & 61.07 & 18.9 \\
5 & 13.48 & 1.7 & 13 & 173.83 & 21.9 \\
6 & 19.64 & 2 & 14 & 168.56 & 22.2 \\
7 & 19.32 & 2.6 & 15 & 223.50 & 37.7 \\
8 & 28.18 & 3.2 & 16 & 214.19 & 120.1 \\ \hline \hline \end{tabular}
\end{table} 
Table 9: Assembling time of 16 small groups. The increase in OET exhibited the strongest correlation with the increase in OTJT, with a correlation coefficient of 0.916. Additionally, apart from OET, the increase in OTJT showed significant correlation with assembling time, with a correlation coefficient of 0.589.