A polyurethane based asphalt composition includes an asphalt component and a polyurethane resin system that is the reaction product of an isocyanate component that includes at least one polyisocyanate and an isocyanate-reactive component that includes a cardanol-modified epoxy polyol. The cardanol-modified epoxy polyol is a reaction product of an epoxy component and an epoxy-reactive component at a ratio of epoxy groups to epoxy reactive groups from 1:0.95 to 1:5. The epoxy-reactive component includes a cardanol component.