A comparison of static and cyclic triaxial test results on railroad ballast was made to develop methods for predicting the properties under repeated load using static test results. The stress-strain-volume-change relationships and strength parameters were measured in drained static and drained cyclic tests. Under cyclic load, the plastic strain response was shown to be much more dependent on material physical state, stress history, and stress path than the elastic response. For all of the conditions tested, the permanent strain after any number of cycles was found to be a function only of the permanent strain after the first cycle, and the number of cycles. The effects of ballast type and density state were thus accounted for by the first cycle behavior. The first cycle strain was estimated from static stress-strain test results using hyperbolic parameters. Refs.