国际糙度指标（International Roughness Index，缩写IRI），是依据「从纵剖面测量计算道路国际粗糙度指数的标准操作规程」（ASTM E 1926-98）创建的标准，常用于测量道路平坦度的指标。当IRI为0表示该剖面非常平坦。一般认为数值超过8m/Km就属于行驶困难、或需减速的坏路。
英语百科
International Roughness Index 国际糙度指标
The International Roughness Index (IRI) is the roughness index most commonly obtained from measured longitudinal road profiles. It is calculated using a quarter-car vehicle math model, whose response is accumulated to yield a roughness index with units of slope (in/mi, m/km, etc.). Since its introduction in 1986, IRI has become the road roughness index most commonly used worldwide for evaluating and managing road systems.