1.1?This test method covers the measurement of a longitudinal profile of a travelled surface using a static level for the purpose of obtaining a road roughness index. This test method is suitable for all surface types that are travelled by conventional ground vehicles, including paved and unpaved roads.

1.2?This test method is labor intensive with respect to other means for measuring longitudinal profile, and is used mainly for (1) validating other profile measuring methods, and (2) calibrating response-type roughness measuring systems.

1.3?This test method describes the computation required for one particular type of roughness index, the vehicle simulation used in the International Roughness Index (IRI). Additionally, the profile obtained with this test method can be processed to obtain other roughness measures.

1.4?This test method includes two levels of accuracy that can be chosen according to need. The more accurate, designated as Class 1, reduces the measurement error of the roughness index to less than 2?% of the true value of the index. The second, designated as Class 2, involves errors less than 5?%.

1.5?The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

1.6?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.

1.7?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.