IRI Roughness Index Calculator

Calculate International Roughness Index (IRI) from road profile data. IRI < 1.5 m/km: very good (new pavement). IRI 1.5-3.0: good. IRI 3.0-5.0: fair. IRI > 5.0: poor. Vehicle dynamic response model (quarter car).

2D stress state at a point. All stresses in MPa.

σx — Normal Stress X (MPa)
σy — Normal Stress Y (MPa)
τxy — Shear Stress (MPa)
⚙ Mechanical Note: Results are based on standard textbook formulas and ISO/AASHTO references. Always verify critical designs with applicable codes (ISO 898, AASHTO 1993, AISC, Eurocode 3) and a qualified engineer.
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How It Works

Calculate International Roughness Index (IRI) from road profile data. IRI < 1.5 m/km: very good (new pavement). IRI 1.5-3.0: good. IRI 3.0-5.0: fair. IRI > 5.0: poor. Vehicle dynamic response model (quarter car)

Each component has a specific meaning:

  • Road profile data — The road profile data recorded for the patient or scenario being assessed.

Note: Interpret the iri roughness result against the clinical thresholds and context described above.

How to Use

Enter the road profile data for the patient or scenario you are assessing. Calculate International Roughness Index (IRI) from road profile data. IRI < 1.5 m/km: very good (new pavement). IRI 1.5-3.0: good. IRI 3.0-5.0: fair. IRI > 5.0: poor. Vehicle dynamic response model (quarter car). Use the iri roughness result to inform your clinical assessment.

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Frequently Asked Questions