Abstract
The International Roughness Index (IRI) has become a well-recognized standard for measurement of road roughness. The main objective of the study was to determine if the Ontario Ministry of Transportation, after ten years of measuring roughness with a response-type roughness measurement system, should switch to the IRI. As part of the study, a variety of roughness measurements, both subjective and objective, were carried out on a set of ten typical pavment sections. The subjective roughness measurements included mean panel rating for cars and a rating for trucks in terms of Ride Comfort Rating (RCR). The objective measurements consisted of three IRI-measuring systems and two response-type measuring systems. (A)