## 5 Field Test Configuration and Results
### Results of Geometric Similarity Evaluation
#### 5.3.2 Results of Scenario Representativeness Evaluation  
To determine whether a specific scenario can represent other scenarios, we evaluated the similarity between different scenarios. To this end, we calculated the parameter applicability index \((A_{m})\) and correlation index \((C_{m})\) for different speeds using Equations (51)-(53) (Section 4.2) and visualized them in a spider chart along with the dynamic correlation index \((D_{k})\), scenario-based applicability index \((A_{k})\), and scenario-based correlation index \((C_{k})\). Table 10 summarizes the scenario representativeness vectors for each test scenario. Based on these multidimensional vectors, we performed two types of comparison: the same-speed comparison focused on the geometric similarity between scenarios under the same speed conditions (low, medium, or high), while the different-speed-condition comparison involved evaluating the geometric similarity between scenarios across different speed conditions (low-medium, medium-high, and high-low) to systematically determine the generalizability of representative scenarios across speed ranges. The results of this comparison are summarized in Table 11 and presented as heat maps in Figure 10. Figure 11 provides an intuitive visualization of the same results through spider charts. \begin{table}
\begin{tabular}{c c c c c c c c c c c c c c} \hline \hline \multicolumn{1}{c}{\multirow{2}{*}{
\begin{tabular}{c} **Scenario A** \\ **Speed SR\({}_{A}\)** \\ **Low** \\ **Mid** \\ **High** \\ **High** \\ **Scenario B** \\ **Speed SR\({}_{C}\)** \\ **Low** \\ **Mid** \\ **High** \\ **Scenario C** \\ **Low** \\ **Mid** \\ **High** \\ **Scenario B** \\ **Speed SR\({}_{C}\)** \\ **Low**  
The similarity indices across most scenario combinations showed minimal differences in both the same-speed and different-speed comparisons. This can be interpreted in two ways. First, the inherent dynamic characteristics of a scenario influence the similarity index more than speed changes. This suggests the possibility of using representative scenarios for testing across various speed conditions. Second, the slightly higher similarity observed in the same-speed comparisons quantitatively demonstrates that speed changes cause small geometric deformations in the scenario characteristics. While these differences were not statistically significant within the range of the test data used in this study, they could be amplified under extreme conditions, such as high-speed driving; this highlights the need for experimental validation across a wider range of speeds. The results reveal high similarity scores in Scenarios E and F, which must be interpreted based on the fundamental principles of vehicle dynamics. Integrated scenarios include complex interactions between lateral and longitudinal behaviors, inducing situations where extreme changes in individual behaviors offset each other. This phenomenon allows integrated scenarios to maintain substantial similarity to single-behavior scenarios. Thus, integrated scenarios reflect characteristics emerging from dynamic interactions rather than simply being arithmetic combinations of individual behaviors. The consistently low similarity index for Scenario D has important theoretical and practical implications. It reflects the fundamental characteristic that longitudinal behavior is more sensitive to speed changes than other behaviors, a phenomenon stemming from the nonlinearity of vehicle dynamics. Longitudinal following behavior is governed by nonlinear relationships between relative speed, acceleration, and any resulting braking and acceleration control inputs. Speed variations amplify this nonlinearity, significantly deforming the relevant geometric shapes within the parameter space. In contrast, lateral behavior maintains relatively stable geometric patterns because the associated steering control characteristics are less sensitive to speed changes. Therefore, Scenario D requires a more systematic verification approach than a single representative scenario.