<p>Traditionally, road construction depends on natural, virgin aggregates, which are becoming scarcer, creating a need for alternative and sustainable replacements. Wastes and industrial byproducts show potential for incorporation in pavement structures, preventing landfill disposal and reducing reliability on natural resources, while ensuring adequate performance. Geosynthetics provide increased strength and durability, offering cost-effective and sustainable solutions for roads. This paper assesses benefits of combining an aggregate with exhausted sands and geogrids for unpaved forest roads. It includes: geotechnical characterisation of two exhausted sands, including their shear behaviour and load-bearing response; design of an unpaved forest road section for different foundation scenarios, considering different solutions for the base layer using unbound materials (aggregate, exhausted sands), without and with geogrid reinforcement; and a cost analysis of solutions designed for a particular case study. The physical and geotechnical characterisation of the exhausted sands demonstrates that their geotechnical application was viable, and that there were no statistical differences between the two exhausted sands. All the solutions were optimised by the inclusion of geogrids, which result in a significant reduction in the height of the base layer. Results also showed that, for the case study considered, using these materials over traditional aggregates is more cost-effective when the transport distances for exhausted sands supply do not surpass 200&#xa0;km. Above this distance, if traditional aggregates are obtained at a shorter distance, profitability is reversed. In all solutions the use of geogrid further enhances cost savings in acquisition and transport.</p>