Haulage operations represent one of the most energy-intensive and cost-critical activities in opencast coal mining. Inefficient haul road design leads to increased rolling resistance, higher truck cycle time, excessive fuel consumption, and accelerated wear of heavy earth-moving machinery (HEMM). This study examines the influence of haul road geometry parameters, including gradient, width, curvature, and surface condition, on the fuel consumption and productivity of haul trucks operating in opencast coal mines. An integrated approach combining field observations, haul cycle analysis, and road condition assessment was used to evaluate the relationship between road geometry and truck performance. The analysis reveals that poorly maintained haul roads and increased rolling resistance significantly affect fuel consumption and operational efficiency. The results demonstrate that optimised haul road design, proper maintenance practices, and improved surface conditions can reduce fuel consumption by 10–15% while enhancing productivity and equipment life. The findings of this research provide practical recommendations for mine planners and engineers to improve transportation efficiency and support sustainable mining operations.