RELATIONSHIPS BETWEEN INTERNATIONAL ROUGHNESS INDEX AND PRESENT SERVICEABILITY RATING

Relationships were developed between the international roughness index (IRI) and the present serviceability rating (PSR) for flexible, rigid, and composite pavement types. PSR is defined as the mean user panel rating for rideability on the conventional 0 to 5 scale. Relationships between IRI and PSR were developed for each pavement type for the states of Louisiana, Michigan, New Jersey, New Mexico, Ohio, and Indiana, and for all six states together. There were no significant differences between the models for different states and pavement types. A nonlinear model that fits the boundary conditions is recommended.