TRANSPORT|land transport|land transport · INDUSTRY|building and public works|public works
- innéacs idirnáisiúnta gairbhe Reference Faomhadh an téarma seo mar chuid de Thionscadal Lex
- ga
- IRI Reference Faomhadh an téarma seo mar chuid de Thionscadal Lex
- ga
- International Roughness Index | IRI
- en
- Definition mathematically defined summary statistic of the longitudinal profile in the wheelpaths of a travelled road surface Reference "Unpaved Roads’ Roughness Estimation by Subjective Evaluation. Rodrigo S. Archondo-Callao. The World Bank. Infrastructure Notes: Transport, Water and Urban Development. October 1999 Transport No. RT-2, http://www4.worldbank.org/afr/ssatp/Resources/HTML/Models/RED_3.2/RED_Additional_Reference_Materials/InfrastructureNote_rt2.pdf [14.1.2012]"
- Comment The IRI describes a scale of roughness which is zero for a true planar surface, increasing to about 2 for paved roads in good condition, 6 for a moderately rough paved roads, 12 for extremely rough paved roads, and up to about 20 for extremely rough unpaved roads. On paved roads, roughness increases continuously over a year if maintenance is not applied. Roughness is generally measured with instruments, and one measurement on a paved road is sufficient to characterize the average annual roughness. On unpaved roads, however, roughness varies over a year as a function of the season, the changing location of the wheelpaths chosen by the vehicles, and the number and the effects of gradings and other maintenance activities.