A new study from the Alaska University Transportation Center, University of Alaska Fairbanks, recently reported on R-values measured on insulation removed from below-grade applications in harsh climates. This supplements data from two previous similar research projects. All the three studies reported the in-service R-values per inch of extruded polystyrene (XPS) and expanded polystyrene (EPS) insulation installed under roads and airport runways with the time in-service ranging from one to 31 years.