This article describes how road profiling technology enables engineers to assess the roughness of in-place concrete and asphalt pavements, in addition to setting benchmarks for newly laid pavement. It relates how the International Roughness Index (IRI), a standard scale used for quantifying the roughness of roads, was developed by researchers at the University of Michigan Transportation Research Institute (UMTRI) Engineering Research Division. The IRI is determined by measuring the profile along the wheel paths of the road, followed by filtering the profiles through a quarter-car mathematical model in order to simulate the suspension deflection of a passenger car. The article discusses how results collected from profilers are calibrated and standardized. Methods for computing a profile index are also discussed. The article concludes with a discussion regarding how road profile data can be used in further road research and vehicle design.
Abstract