## 6 Results and Discussion
### Correction of Asphalt Pavement Rutting Prediction Model
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**Structure Type** & \(\beta_{1}\) & \(\beta_{2}\) & \(\beta_{3}\) & **MSE** & **RMSE** & **MAE** & **MAPE** & \(R^{2}\) \\ \hline I & STR1 & 6.1319 & 1.2123 & 0.5440 & 0.21 & 0.46 & 0.38 & 8.6\% & 0.9331 \\  & STR2 & 6.1201 & 1.2120 & 0.5425 & 0.18 & 0.42 & 0.31 & 7.4\% & 0.9400 \\ II & STR4 & 9.4764 & 1.2749 & 0.3677 & 0.11 & 0.33 & 0.24 & 6.6\% & 0.8722 \\  & STR5 & 7.5312 & 1.2573 & 0.4409 & 0.13 & 0.36 & 0.26 & 6.4\% & 0.9237 \\ III & STR7 & 7.0638 & 1.2254 & 0.5330 & 0.31 & 0.56 & 0.40 & 8.2\% & 0.9415 \\  & STR8 & 5.4336 & 1.1970 & 0.6079 & 0.30 & 0.55 & 0.39 & 7.5\% & 0.9591 \\ IV & STR10 & 7.2853 & 1.2287 & 0.5340 & 0.47 & 0.69 & 0.49 & 10.1\% & 0.9203 \\ IV & STR12 & 10.0245 & 1.2674 & 0.4357 & 0.41 & 0.64 & 0.48 & 10.6\% & 0.8787 \\ V & STR11 & 7.0344 & 1.2237 & 0.5301 & 0.34 & 0.59 & 0.46 & 8.7\% & 0.9311 \\  & STR13 & 9.6484 & 1.2624 & 0.4367 & 0.31 & 0.56 & 0.42 & 9.2\% & 0.9045 \\ VI & STR16 & 9.9075 & 1.2660 & 0.4412 & 0.31 & 0.55 & 0.39 & 10.0\% & 0.8901 \\  & STR17 & 8.2984 & 1.2436 & 0.4598 & 0.24 & 0.49 & 0.38 & 9.6\% & 0.8913 \\  & STR18 & 4.8346 & 1.1941 & 0.5643 & 0.46 & 0.68 & 0.52 & 10.8\% & 0.9312 \\ VII & STR19 & 6.9198 & 1.2416 & 0.4625 & 0.25 & 0.50 & 0.37 & 7.9\% & 0.9073 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Local correction coefficients and errors of rutting model. about 4-6 mm. After that, due to the limited compressible voids inside the asphalt mixture, when the voids can no longer be compressed, the asphalt mixture begins to produce plastic permanent deformation. Compared with the compaction deformation, the increase of the plastic deformation is relatively slow and not as rapid as the compaction deformation in the initial stage. As can be seen from Figure 7, although the overall change in trend of the new and old models is in the form of a monotonically increasing power function, the new model has a steeper curve shape in the initial loading stage, which can better simulate the initial compaction deformation of asphalt mixture when \(N_{e}\) is from 0 to 5 million ESALs. As seen in Equation (7), correction coefficients \(\beta_{1}\) and \(\beta_{2}\) respectively correct the constant term of the model and the exponential term of the equivalent temperature, and the equivalent temperature is fixed for the same structure, so the coefficient \(\beta_{2}\) can also be regarded as a correction to the constant term. According to the results in Table 4, it can be seen that when correction coefficients \(\beta_{1}\) and \(\beta_{2}\) are introduced, the constant term of the new model is numerically at least approximately 6 times higher than that of the old model. In addition, when the initial loading stage is over, the evolution curve of the second stage of the new model is smoother than that of the old model, and it can better simulate the slowly increasing plastic permanent deformation, and the model prediction effect is also better. It can be seen from Equation (7) that \(\beta_{3}\) mainly corrects the exponential term of \(N_{e}\), and \(N_{e}\) is also the only independent variable in Equation (7), and the evolution curve in the second stage of the model mainly depends on the value of the exponential term. The smaller the value, the smoother the curve. From the values in Table 4, it can be seen that the average value of \(\beta_{3}\) is about 0.5, the exponential term of the new model is half of that of the old model, and its curve is gentler, which can better simulate the slowly increasing plastic permanent deformation after the initial loading stage. It should be noted that the measured rutting data of 14 kinds of structures in Figure 6 are obtained based on the accelerated loading test of the RIOHITrack's full-scale pavement structure. Since the test section is built in the wild, it has always been bearing the long-term effect of the local climate environment, and the pavement structure and material type are  
Figure 7: Comparison of predicted and measured values before and after rutting model correction.