The use of lightweight-fill materials for highway construction increased significantly worldwide during the 1990s. Predominant with this trend was the increased use of cellular geosynthetics (geofoams and geocombs), especially block-molded expanded polystyrene (EPS) geofoam, on highway and bridge embankments. EPS geofoam is increasingly recognized as an important tool for reducing overall cost of highways through "accelerated construction". Thus, it was appropriate that lightweight-fill materials, mostly EPS, were the materials of choice on Boston’s Central Artery/Tunnel (CA/T) Project, commonly known as the "Big Dig". EPS highway embankments have been constructed, as part of a cost-and schedule-initiative, replacing the original design concepts for eight transition highway structures on a recent CA/T construction contract