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

Importancia y uso:

5.1 This practice provides a means for obtaining a quantitative estimate of a pavement property defined as roughness using longitudinal profile measuring equipment.

5.1.1 The IRI is portable in that it can be obtained from longitudinal profiles obtained with a variety of instruments.

5.1.2 The IRI is stable with time because true IRI is based on the concept of a true longitudinal profile, rather than the physical properties of a particular type of instrument.

5.2 Roughness information is a useful input to the pavement management systems (PMS) maintained by transportation agencies.

5.2.1 The IRI for the right wheel track is the measurement of road surface roughness specified by the Federal Highway Administration (FHWA) as the input to their Highway Performance Monitoring System (HPMS).

5.2.2 When profiles are measured simultaneously for both traveled wheel tracks, then the MRI is considered to be a better measure of road surface roughness than the IRI for either wheel track.

Note 1: The MRI scale is identical to the IRI scale.

5.3 IRI can be interpreted as the output of an idealized response-type measuring system (see Test Method E1082 and Specification E1215), where the physical vehicle and instrumentation are replaced with a mathematical model. The units of slope correspond to accumulated suspension motions (for example, metres), divided by the distance traveled (for example, kilometres).

5.4 IRI is a useful calibration reference for response-type systems that estimate roughness by measuring vehicular response (see Test Method E1082 and Specification E1215).

5.5 IRI can also be interpreted as average absolute slope of the profile, filtered mathematically to modify the amplitudes associated with different wavelengths (3).

Subcomité:

E17.33

Referida por:

E1448_E1448M-09R23, E2133-03R20, E0867-23, E0950_E0950M-22, E1777-09R24

Volúmen:

04.03

Número ICS:

93.080.99 (Other standards related to road engineering)

Palabras clave:

highway performance monitoring system; HPMS; international roughness index; International Roughness Index; longitudinal profile; pavement management systems; pavement roughness; PMS;