# Analysis and Verification Results of Manual Inspection of Pavement Condition Index
## 3 Results
### Comparison of Inspection Data
#### 3.1.2 Inspection Data After Training  
After undergoing professional training, the inspectors performed multiple PCI measurements on the same road segments to evaluate the impact of the training on inspection accuracy and repeatability. The training focused on enhancing inspection techniques, strengthening the understanding of standard operating procedures, and minimizing errors caused by subjective judgment.  
Each inspector conducted four measurements after the training, with the results fully recorded and compared to the pre-training data. To quantify the improvements in inspection performance due to training, this section analyzes the accuracy and repeatability of the post-training inspection data. Key comparison metrics include the Mean Relative  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Inspector** & **First** & **Second** & **Third** & **Fourth** & **SD** & **CV (\%)** \\ \hline Inspector A & 52.0 & 30.7 & 42.8 & 30.9 & 6.93 & 19.9\% \\ Inspector B & 10.3 & 6.2 & 4.9 & 12.6 & 3.24 & 33.4\% \\ Inspector C & 24.2 & 16.2 & 15.9 & 18.6 & 1.48 & 8.8\% \\ Inspector D & 14.2 & 44.6 & 15.3 & 22.1 & 15.34 & 56.1\% \\ \hline \hline \end{tabular}
\end{table}
Table 2: Repeatability data of inspectors before validation.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Inspector** & **Measured Data** & **Average** & **Relative Error (\%)** \\ \hline \multirow{3}{*}{Inspector A} & 30.7 & 38.41\% \\ \cline{2-4}  & 42.8 & 92.97\% \\ \cline{2-4}  & 30.9 & 39.31\% \\ \hline \multirow{3}{*}{Inspector B} & 10.3 & 53.56\% \\ \cline{2-4}  & 6.2 & 72.05\% \\ \cline{2-4}  & 12.6 & 43.19\% \\ \hline \multirow{3}{*}{Inspector C} & 16.2 & 26.96\% \\ \cline{2-4}  & 15.9 & 28.31\% \\ \cline{2-4}  & 18.6 & 16.14\% \\ \hline \multirow{3}{*}{Inspector D} & 44.6 & 101.08\% \\ \cline{2-4}  & 15.3 & 31.02\% \\ \cline{2-4}  & 22.1 & 0.36\% \\ \hline \multicolumn{3}{c}{Average} & 45.28\% \\ \hline \hline \end{tabular}
\end{table}
Table 3: Accuracy data of inspectors before validation.  
Error (MRE) and the Coefficient of Variation (CV), which reflect the consistency and stability of the inspection data.  
The post-training inspection results demonstrate a significant reduction in the Coefficient of Variation (CV). Table 4 lists the CVs for the four measurements conducted by each inspector. Compared to the pre-training results, Inspector D's CV decreased notably from 56.1% to 8.8%, indicating a substantial improvement in data repeatability. This suggests that, following the training, all inspectors were able to adhere more closely to the standard operating procedures, thereby reducing variability and individual differences in the measurement results.  
The accuracy after training also showed significant improvement. As shown in Table 5, the Mean Relative Error (MRE) between each inspector's results and the standard PCI score decreased notably after training. The post-training average MRE dropped to 5.88%, compared to 45.28% before training, representing a substantial improvement. This indicates that the training enabled inspectors to more accurately identify and assess pavement conditions, thereby reducing the impact of human errors.