This paper gives an overview of road roughness technology, lists the most prominent equipment used in longitudinal profile evaluations, and discusses uses of the measurements. Several types of roughness measurement equipment are operational for the purpose of measuring riding quality; whereas, development of equipment, data reduction procedures, and meaningful acceptance criteria of roughness for highway safety, for predicting pavement loading from heavy vehicles, and for determining pavement life expectancy have not reached the point where the equipment and procedures are operational for large scale road inventory purposes.