Design of shallow foundations on soils is most often governed by settlement or Service Limit State (SLS) rather than the bearing capacity restrictions, i.e. Ultimate Limit State (ULS). In an effort to develop the SLS design specifications under the National Cooperative Highway Research Program NCHRP project 12-66 (AASHTO LRFD specifications for the serviceability in the design of bridge foundation), a large database of case histories of shallow foundation load tests has been assembled in MS ACCESS platform. Out of the 329 case histories compiled, only those related to granular materials and which include Standard Penetration Test (SPT) results have been utilized. These cases, being most relevant to bridge foundation design (soil type and site investigation), have been used for analyzing the uncertainty in the relationship between the measured to calculated loads for given displacements.