# Prediction of Friction Coefficient Based on 3D Texture Characteristics of Road Surfaces
## 3 Results and Discussion
### Assessment of Surface Texture Metrics  
For each surface, more than eighty different parameters were calculated. Table 2 provides examples of the calculated parameters, selected based on their statistical significance in the later-created prediction model. For clarity, the table presents data rounded to one, or two decimal places, though all decimal places were used in the analysis.  
Figure 7 illustrates examples of the scans and surfaces on selected measurement sections.  
\begin{table}
\begin{tabular}{c c c c c c c c c c c c c c c c c c c} \hline \hline \multicolumn{13}{c}{**Characteristics**} & \multicolumn{13}{c}{**Road Section**} \\ \cline{2-13}  & **1** & **2** & **3** & **4** & **5** & **6** & **7** & **8** & **9** & **10** & **11** & **12** & **13** & **14** & **15** & **16** & **17** \\ \hline \multirow{4}{*}{\(S_{mT,MIC}\)} & MIN & 13.0 & 12.8 & 13.1 & 14.1 & 11.4 & 11.0 & 11.1 & 11.8 & 11.3 & 11.6 & 13.6 & 12.2 & 13.3 & 11.6 & 11.6 & 11.5 & 11.6 \\  & MAX & 14.0 & 13.4 & 14.3 & 14.5 & 12.3 & 11.9 & 11.9 & 13.4 & 12.5 & 13.2 & 14.6 & 13.1 & 14.3 & 12.4 & 12.1 & 12.0 & 11.9 \\  & AVER. & 13.2 & 13.1 & 13.7 & 14.2 & 11.9 & 11.5 & 11.5 & 12.5 & 11.9 & 12.3 & 13.9 & 12.8 & 13.8 & 11.9 & 11.8 & 11.6 & 11.7 \\  & SD & 0.29 & 0.19 & 0.41 & 0.13 & 0.30 & 0.30 & 0.28 & 0.51 & 0.37 & 0.47 & 0.30 & 0.29 & 0.31 & 0.23 & 0.15 & 0.15 & 0.13 \\ \hline \multirow{4}{*}{\(S_{mT,MIC}\)} & MIN & 84.6 & 84.5 & 85.1 & 84.8 & 85.8 & 86.3 & 86.5 & 84.7 & 83.9 & 83.9 & 83.1 & 83.4 & 83.4 & 85.7 & 86.4 & 85.8 & 85.7 \\  & MAX & 85.2 & 85.0 & 86.2 & 85.6 & 86.6 & 87.3 & 87.1 & 85.8 & 85.7 & 85.0 & 84.7 & 84.2 & 84.3 & 86.1 & 86.6 & 86.4 & 86.3 \\  & AVER. & 84.9 & 84.8 & 85.6 & 85.2 & 86.2 & 86.8 & 86.8 & 85.3 & 84.6 & 84.4 & 83.8 & 83.7 & 83.9 & 85.9 & 86.5 & 86.1 & 86.0 \\  & SD & 0.20 & 0.19 & 0.32 & 0.29 & 0.25 & 0.39 & 0.26 & 0.38 & 0.68 & 0.34 & 0.47 & 0.25 & 0.32 & 0.18 & 0.09 & 0.15 & 0.21 \\ \hline \multirow{4}{*}{\(S_{pc,MAC}\)} & MIN & 1.45 & 1.40 & 1.38 & 1.50 & 1.46 & 1.16 & 1.14 & 1.31 & 0.56 & 0.49 & 1.34 & 1.18 & 1.22 & 1.44 & 1.58 & 1.38 & 1.52 \\  & MAX & 1.62 & 1.57 & 1.70 & 1.72 & 2.04 & 1.80 & 1.52 & 1.99 & 0.83 & 0.81 & 1.75 & 1.46 & 1.39 & 1.76 & 2.20 & 1.63 & 1.70 \\  & AVER. & 1.52 & 1.48 & 1.53 & 1.60 & 1.70 & 1.43 & 1.31 & 1.62 & 0.70 & 0.67 & 1.53 & 1.32 & 1.31 & 1.59 & 1.83 & 1.50 & 1.62 \\  & SD & 0.07 & 0.05 & 0.09 & 0.08 & 0.18 & 0.19 & 0.11 & 0.26 & 0.08 & 0.10 & 0.15 & 0.09 & 0.07 & 0.10 & 0.18 & 0.09 & 0.07 \\ \hline \multirow{4}{*}{\(S_{mc,PS}\)} & MIN & 0.62 & 0.48 & 0.54 & 0.50 & 0.81 & 0.90 & 0.70 & 1.12 & 0.37 & 0.35 & 1.28 & 0.79 & 0.93 & 0.87 & 0.85 & 0.74 & 0.72 \\  & MAX & 0.70 & 0.60 & 0.63 & 0.66 & 1.22 & 1.39 & 1.18 & 1.79 & 0.58 & 0.59 & 1.93 & 0.93 & 1.29 & 1.16 & 1.02 & 1.03 & 1.17 \\  & AVER. & 0.65 & 0.53 & 0.58 & 0.58 & 1.03 & 1.19 & 0.85 & 1.42 & 0.44 & 0.46 & 1.59 & 0.86 & 1.06 & 0.98 & 0.93 & 0.84 & 0.88 \\  & SD & 0.03 & 0.03 & 0.03 & 0.05 & 0.15 & 0.15 & 0.15 & 0.21 & 0.07 & 0.08 & 0.17 & 0.05 & 0.12 & 0.08 & 0.06 & 0.10 & 0.15 \\ \hline \multirow{4}{*}{\(V_{\text{proj,PS}}\)} & MIN & 0.09 & 0.07 & 0.09 & 0.09 & 0.15 & 0.07 & 0.06 & 0.08 & 0.03 & 0.04 & 0.11 & 0.06 & 0.09 & 0.09 & 0.09 & 0.09 & 0.10 \\  & MAX & 0.12 & 0.09 & 0.12 & 0.12 & 0.32 & 0.14 & 0.09 & 0.16 & 0.09 & 0.11 & 0.19 & 0.11