In order to compare subjective and objective assessments, a passenger car was driven at several speeds over several road profiles. To measure the acceleration signals experienced by the seated subject who provided an subjective assessment, four triaxial translational accelerometers and one triaxial gyro sensor were mounted on the steering wheel and on the passenger seat and floor, respectively. Correlations were determined between the measured accelerations and the subjective assessments of 3 expert subjects and 9 general subjects using psychophysical power law.