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ASTM E1926-08(2021)

Standard Practice for Computing International Roughness Index of Roads from Longitudinal Profile Measurements

1.1 This practice covers the mathematical processing of longitudinal profile measurements to produce a road roughness statistic called the International Roughness Index (IRI).

1.2 The intent is to provide a standard practice for computing and reporting an estimate of road roughness for highway pavements.

1.3 This practice is based on an algorithm developed in the International Road Roughness Experiment sponsored by a number of institutions including the World Bank and reported in two World Bank Technical Papers (1, 2).2 Additional technical information is provided in two Transportation Research Board (TRB) papers (3, 4).

1.4 The values stated in SI units are to be regarded as the standard. The inch-pound units given in parentheses are for information only.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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