<p>This study presents a numerical investigation of culvert systems’ performance by including a compressible layer over the box culverts. A numerical model was developed using ABAQUS software and validated with experimental results. Following that, parametric studies were conducted to examine the influence of the EPS barrier’s geometrical and mechanical properties on the culverts’ structural behavior. The findings show that the distribution of transferred pressure and bending moments along the culvert walls varies nonuniformly. EPS geofoam effectively mitigates transferred pressure and reduces bending moments on the culvert walls, improving structural performance. Geometrical and mechanical properties of the EPS barrier, such as width, thickness, elastic modulus, and distance, significantly affect the behavior of the culvert system. The knowledge gained can assist engineers in making informed decisions to improve the structural efficiency of buried box culverts; however, some adverse effects may occur for the sidewall of the buried culvert.</p>