Relationships between international roughness index and present serviceability rating

This paper documents relationships between the international roughness index (IRI) and the present serviceability rating (PSR) for pavement types included in the FHWA Highway Planning and Monitoring System (HPMS) data base. FHWA has requested that states report roughness data in the form of the IRI, which was developed by the World Bank in an effort to provide consistent data about roughness. The IRI is an objective and consistent measure of pavement condition that was chosen as the HPMS standard reference roughness index to provide more consistency between states. FHWA directed all states to report pavement roughness data by IRI for all paved rural arterials and urban freeways and ex. pressways, including Interstates, beginning in 1989.