<div class="htmlview paragraph">A facility which duplicates the random road profile in the laboratory fatigue testing of a complete vehicle structure is presented. A road simulated endurance test can be conducted with this facility, which utilizes magnetic tape command to electro-hydraulic shakers.</div> <div class="htmlview paragraph">The complete test program of a vehicle is described. The program includes recording the random road inputs to the vehicle suspension, duplication of these random inputs with the facility to effect a fatigue test evaluation of the vehicle structure, and validation of the test by power spectral density and peak level counting techniques. The facility yields acceptable correlation between laboratory and proving ground fatigue failures, with a significant reduction in test time.</div>