# Fuel-Efficient Road Classification Methodology for Sustainable Open Pit Mining
## 5 Conclusions  
Road quality is a critical factor affecting truck transportation efficiency and costs in open-pit coal mines. Currently, road quality assessment in such mines relies primarily on driver feedback. This study proposes an innovative fuel-efficient road classification method, quantifying the relationship between road quality and truck fuel consumption. The findings provide a systematic approach for evaluating and constructing haul roads in open-pit coal mines, offering both economic and operational benefits. To elaborate, the proposed methodology initiated with the acquisition of an overall point cloud model of the mining site using a UAV. Subsequently, this point cloud model undergoes conversion into a DEM. The mine design software 3 DMINE was then deployed to capture road roughness sampling points at 1 m intervals. The ensuing stage encompasses the substitution of these sampling points into the IRI model, facilitating the determination of appropriate road division intervals. This is followed by the establishment of a linear relationship between fuel consumption and IRI through regression analysis. Finally, the k-means algorithm was used to classify the fuel consumption, with the intervening nodes integrated into the linear relationship. This ultimately led to the classification of IRI, culminating in the categorization of road types as fuel-efficient. This study takes the Haerwusu Open-Pit Coal Mine as a case study, selecting two haul roads each from the mining area, dump site, and non-working area to establish road classifications. The results IRI values of 12 and 20 serve as thresholds for classifying poor, moderate, and good roads under loaded truck conditions, while thresholds of 15 \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & \multicolumn{4}{c}{**Loaded Trucks**} & \multicolumn{4}{c}{**Unloaded Trucks**} \\ \hline \multirow{4}{*}{**Upgraded IRI**} & \multirow{2}{*}{\begin{tabular}{c} **Fuel Consumption** \\ **(L/100 km)** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Cost** \\ **(CNY)** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Upgraded IRI** \\ **(CNY)** \\ \end{tabular} } & \multirow{2}{*}{\
\begin{tabular}{c} **Fuel Consumption** \\ **(L/100 km)** \\ \end{tabular} } & \multirow{2}{*}{
\begin{tabular}{c} **Cost** \\ **(CNY)** \\ \end{tabular} } \\ \hline \multirow{8}{*}{Road 1} & 16.00 & 1926.40 & 21.38 & 18.00 & 1450.58 & 16.10 \\  & 16.00 & 1926.40 & 21.38 & 18.00 & 1450.58 & 16.10 \\  & 19.04 & 1969.71 & 21.86 & 19.04 & 1460.78 & 16.21 \\  & 17.41 & 1946.49 & 21.61 & 17.41 & 1444.81 & 16.04 \\  & 18.62 & 1963.76 & 21.80 & 18.62 & 1456.68 & 16.17 \\  & 16.00 & 1926.40 & 21.38 & 18.00 & 1450.58 & 16.10 \\  & 18.70 & 1964.86 & 21.81 & 18.70 & 1457.44 & 16.18 \\  & 16.00 & 1926.40 & 21.38 & 20.57 & 1475.73 & 16.38 \\  & 15.07 & 1913.09 & 21.24 & 15.07 & 1421.85 & 15.78 \\  & 19.35 & 1974.15 & 21.91 & 19.35 & 1463.83 & 16.25 \\ \hline \multirow{8}{*}{Road 2} & 13.45 & 1890.09 & 20.98 & 13.45 & 1406.03 & 15.61 \\  & 16.00 & 1926.40 & 21.38 & 18.00 & 1450.58 & 16.10 \\  & 16.00 & 1926.40 & 21.38 & 20.79 & 1477.90 & 16.40 \\  & 19.11 & 1970.66 & 21.87 & 19.11 & 1461.43 & 16.22 \\  & 16.00 & 1926.40 & 21.38 & 18.00 & 1450.58 & 16.10 \\  & 16.00 & 1926.40 & 21.38 & 18.00 & 1450.58 & 16.10 \\  & 16.00 & 1926.40 & 21.38 & 18.00 & 1450.58 & 16.10 \\  & 11.40 & 1860.91 & 20.66 & 11.40 & 1385.98 & 15.38 \\ \hline \multicolumn{8}{c}{Total fuel costs} & 407.57 & \multicolumn{2}{c}{Total fuel costs} & 305.44 \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Fuel costs after road quality upgraded. and 21 are identified for unloaded truck operations. To evaluate the economic impact of road classification, two additional haul roads in the Haerwusu Open-Pit Coal Mine were selected for comparative analysis. The results demonstrate that the fuel costs for loaded and unloaded conditions decreased to 407.57 CNY and 305.44 CNY, respectively, representing cost savings of 3% and 2%.