## 3 Results and Discussion
### Road DEM Construction with Morphological Expression Priority
The method used in this paper eliminated morphological jitter at the junction of two roads, making the intersection more consistent with the morphological characteristics of its microelevation fluctuation. However, the elevation fluctuations of the two selected sample roads were large, and the gradient at the intersection of the road was greater than 3\({}^{\circ}\), which is consistent with the actual shape of the road. This result indicates that the intersection model constructed by this method conformed to the actual shape of the intersection and improved the morphological fidelity of the road modeling results. The above road DEM and slope demonstrate that the modeling method in this paper is suitable for road modeling, and the results can conform to the morphological characteristics of the road. For quantitative analysis, several road statistics were selected for comparative analysis, and the four indicators of maximum value, minimum value, average value, and maximum elevation fluctuation were used for evaluation (Table 1). Table 1 shows that for the two road sections selected in this paper, the indexes calculated by the DEM obtained by the two methods were approximate. Statistically, the difference in each elevation index was essentially controlled at approximately 0.05 m, and the difference in the average elevation results measured by different methods was not large. However, the maximum elevation fluctuation calculated by the traditional interpolation method (IDW) for the two sections was relatively high, although the method used in this paper appropriately reduced the degree of fluctuation. Therefore, due to the characteristics of flat pavement, strong regularity of elevation change, and high accuracy and density of the modeling data, the road DEM construction method proposed in this paper resulted in no loss of elevation accuracy under the condition that the morphological accuracy was greatly improved, thus improving road smoothness and regularity. For the gradient of the two selected road sections (Table 2), the method in this paper significantly reduced the gradient of the road compared with the traditional interpolation method (IDW). For the flat road, the maximum gradient of the traditional interpolation method (IDW) was approximately 9\({}^{\circ}\), and the gradient of the method used in this paper was controlled within 4\({}^{\circ}\); for the undulating road, the maximum gradient of the traditional interpolation method (IDW) was approximately 11\({}^{\circ}\), while the gradient of the method used in this paper was controlled at approximately 9\({}^{\circ}\). These results indicate that it is essential to smooth the sidelines during road construction, as this can effectively prevent outliers. Overall, the results of this method of construction not only confirmed the elevation accuracy of the DEM, but also showed that the morphological expression accuracy of the road DEM had significantly improved. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline  & \multicolumn{4}{c}{**Traditional Method (IDW)**} & \multicolumn{4}{c}{**Method Used in This Paper**} \\ \cline{2-9}  & **Min.** & **Max.** & **Average** & \
\begin{tabular}{c} **Max.** \\ **Fluctuation** \\ \end{tabular} & **Min.** & **Max.** & **Average** &
\begin{tabular}{c} **Max.** \\ **Fluctuation** \\ \end{tabular} \\ \hline Flat road & 37.46 & 41.38 & 38.82 & 3.92 & 37.53 & 41.35 & 38.82 & 3.82 \\ Undulating road & 39.42 & 64.89 & 49.02 & 25.47 & 39.47 & 64.86 & 48.98 & 25.39 \\ \hline \end{tabular}
\end{table} 
Table 1: Statistics of road elevation index (m).