AASHTO R 56

Description / Abstract: This practice describes a certification procedure for test equipment used to measure a longitudinal surface elevation profile of highways based on an inertial reference system that is mounted on a host vehicle. The minimum requirements stipulated herein are intended to focus on the need for accurate and repeatable profile measurements for construction quality control/quality assurance, acceptance and network-level data collection.

This practice describes minimum performance requirements for inertial profiling systems to be used on Owner-Agency paving projects where a profile-based smoothness specification is applicable and for network data collection programs.

The filtering methods and threshold values recommended in this document were established to ensure adequate determination of the International Roughness Index (IRI) and the profile features that affect it. An Owner-Agency planning to use an index other than the IRI should filter the profile and set thresholds accordingly. In particular, replace the preprocessor filter in Step 3, Appendix X.1 with a filter that corresponds to the relevant waveband for the alternative index.

If any part of this practice is in conflict with referenced documents, such as ASTM Standards, this practice takes precedence for its purposes.

This practice 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 practice to establish appropriate safety and health practices and determine the applicability of regulatory limitations related to and prior to its use.