Paper 1: An analysis is presented of some 6,000 mi of pavement profile obtained by the Michigan pavement performance study in the 3-year period of 1958-59-60. Paper 2: Using the criterion of pavement condition as defined in this paper, it is possible to estimate the dynamic force that one wheel of a vehicle will exert on a highway. Paper 3: The method used to measure road profile and techniques used to establish the accuracy of these measurements are described. Paper 4: Various modifications made by Illinois are described in constructing its roadometer as well as the tests in which it has been subjected and its use in rating Illinois pavements under the present serviceability concept following correlation of the device with the AASHO road test profilometer.

Road roughness is gaining increasing importance as an indicator of road condition, both in terms of pavement performance, and as a major determinant of road user costs. This paper defines roughness measurement systems hierachically into four groups, ranging from profilometric methods (2 groups), through response type road roughness measuring systems (RTRRMS's), and, subjective evaluation. The International Roughness Index (IRI) is defined, and the programs for it's calculation are provided. The IRI is based on simulation of the roughness response of a car travelling at 80 km/h. The report explains how all roughness measurements can be related to this scale, also when travelling at lower speeds than 80 km/h. The IRI emerges as a scale that can be used both for calibration and for comparative purposes.

This report contains guidelines and recommendations for managing and designing for friction on highway pavements. The contents of this report will be of interest to highway materials, construction, pavement management, safety, design, and research engineers, as well as others concerned with the friction and related surface characteristics of highway pavements.