This study evaluates the structural performance of geocell–geotextile reinforced gravel roads constructed on waterlogged subgrades typical of Swedish forest environments. Three full-scale test sections were built: two geocell-reinforced sections using crushed rock and locally sourced material, respectively, and one conventional unreinforced reference section with nearly double structural thickness. Laboratory characterization, lightweight deflectometer (LWD) testing, moisture measurements, surface profiling, and visual inspections were conducted immediately after construction and after eight months of environmental exposure and simulated traffic loading. The geocell-reinforced sections exhibited substantial improvements in bearing capacity, with dynamic deformation modulus (Evd) increases of 52–64% after trafficking compared with the unreinforced section. Profile measurements showed negligible rutting in reinforced sections, while the reference section developed visible deformation despite its greater thickness. The results demonstrate that geocell confinement combined with geotextile separation effectively enhances structural capacity and durability on weak saturated subgrades. Furthermore, the use of locally sourced infill material provided equal or superior performance compared with imported crushed rock, indicating potential for cost reduction and possible environmental benefits through reduced material transport and resource use. The findings support geocell reinforcement as a practical solution for improving accessibility, reducing material demand, and increasing climate resilience of forest gravel roads.