A vehicle floor assembly having a floor panel and a pair of elongated members disposed along opposing sides of the floor panel. A central tunnel extends longitudinally between the pair of elongated members and has an upper surface elevated vertically from a planar extent of the floor panel. A crossmember beam is coupled to and spans between the pair of longitudinal members. The crossmember beam has a cross-sectional shape extending continuously along a length of the crossmember beam. The crossmember beam includes a curved shape along at least a section of the length of the crossmember beam that positions a lower surface of the crossmember beam above the upper surface of the central tunnel.