## 6 Results and Discussion  
Based on the illustrated procedure, EAR index values were calculated for all EPD-certified mixtures analyzed in this study, resulting in the values shown in the following Figure 2. The \(EAR\) values obtained vary in a range from 29.58 to 63.23, demonstrating good variability in the results.  
Figure 1: \(EAR\) and \(EAR_{\text{c}}\) calculation flow chart.  
Figure 2: \(EAR\) values calculated per certified mixtures. Share related to the each impact category reported with different colors.  
As can be seen from data summarized in Table 9, the greatest impact on the composition of the EAR index is due to the raw material production stage, which impacts about 60%, followed by the in-plant production stage, which impacts for 20%. The impact of the transportation (A2 and A4) and material paving phases is the least incisive.  
Based on the available data on the analyzed mixtures, a direct calculation of the \(EAR_{\text{c}}\) is not possible since no such data are available for the considered EPD-certified mixtures. However, to provide a comprehensive example of the application of the proposed methodology, it was decided to derive the corrective parameters from the pre-qualification data available for mixtures similar to Norge Wearing (labeled as MIX1 and MIX2) and Norge Base (labeled as MIX3 and MIX4). The pre-qualification values of the equivalent mixtures are summarized in Table 10 while the derived coefficients \(I_{1}\), \(I_{2}\) a and \(I_{3}\) and the corresponding corrected value of the EAR index are reported in Table 11.  
As visible in Table 11, the value of \(I_{2}\) is equal to 1 for all mixtures as the \(TDC\) coefficient only applies to open-graded mixtures. Even for the \(I_{3}\) coefficient applied to base mixtures (MIX3 and MIX4), the value is the same and equal to 1 since this kind of mixture is not involved in the rolling noise generation process.  
Finally, the obtained values of \(EAR\) and \(EAR_{\text{c}}\) are reported in Figure 3.  
The application of performance coefficients ensures effective differentiation between mixtures. It can be seen that the difference between EAR and \(EAR_{\text{c}}\) is more pronounced for wearing courses than for base courses. This is mainly due to the application of the corrective parameter \(I_{3}\) related to the impact of noise emissions.  
\begin{table}
\begin{tabular}{l l l l l l l l l l l l l l} \hline \hline
**Code** & **Type** & **GG** & **GM** & **PB** & **VA** & **VMA** & **VBEFF** & \(\mathbf{\rho_{34}}\) & \(\mathbf{\rho_{38}}\) & \(\mathbf{\rho_{4}}\) & \(\mathbf{\rho_{200}}\) & **PEN** & **ITS** & **CTI** \\  & & \((\mathbf{g/cm^{3}})\) & \((\mathbf{g/cm^{3}})\) & **orig. \%** & & **\%** & & **\%** & & & & \((\mathbf{MPa})\) & \((\mathbf{MPa})\) \\ \hline MIX1 & Wearing & 2.698 & 2.495 & 5.20 & 3.3 & 15.0 & 9.033 & 0 & 12.8 & 40.6 & 7.1 & 50 & 1.37 & 118.01 \\ MIX2 & Wearing & 2.652 & 2.458 & 5.20 & 3.6 & 15.1 & 8.535 & 0 & 17.6 & 41.4 & 6.8 & 50 & 1.3 & 128.71 \\ MIX3 & Base & 2.673 & 2.499 & 4.50 & 3.5 & 13.8 & 7.217 & 8.7 & 47.4 & 57.5 & 5.1 & 50 & 1.31 & 137.11 \\ MIX4 & Base & 2.681 & 2.505 & 4.50 & 3.6 & 13.7 & 7.169 & 12.6 & 57.2 & 64.5 & 4 & 50 & 1.31 & 108.91 \\ course & & & & & & & & & & & & & & \\ \hline \hline \end{tabular}
\end{table}
Table 10: Pre-qualification values of asphalt mixtures.  
\begin{table}
\begin{tabular}{l l l l l l} \hline \hline
**Xature** & **EAR/t** & **A1** & **A2** & **A3** & **A4**+**A5** \\ \hline French market & 56.64 & 60\% & 10\% & 23\% & 6\% \\ Collosa & 68.28 & 64\% & 6\% & 25\% & 5\% \\ Norge wearing & 62.17 & 69\% & 9\% & 16\% & 6\% \\ Norge base & 57.68 & 63\% & 12\% & 19\% & 6\% \\ \hline \hline  & **Average** & **63**\% & **11**\% & **20**\% & **6**\% \\ \hline \hline \end{tabular}
\end{table}
Table 9: Impact due to the different phases of the production process.