Pavement Condition

The collection of pavement condition data is one of the most important and costly elements of operating a pavement management system (PMS). This function is crucial, as business decisions rely on it: a PMS should be able to prioritize maintenance, rehabilitation, and reconstruction effectively. Pavement condition data are usually transformed into a numerical rating system [a pavement condition index (PCI)] that qualitatively describes individual pavement segments or a network. The Iowa Department of Transportation's PCI is calculated by using PCI equations that are based on statistical regression analysis. Different attributes are used for different pavement families. The study summarized here aimed to develop a new condition index that provides a consistent, unified approach to rating pavements in Iowa. The proposed system has a 100-point scale that is based on five indexes derived from specific distress data or pavement properties and an overall index that combines individual indexes with weighting factors. The indexes cover cracking, ride, rutting, faulting, and friction. The cracking index is formed by combining cracking data (i.e., transverse cracking, longitudinal cracking, wheelpath cracking, and alligator cracking indexes). Ride, rutting, and faulting indexes use the international roughness index, rut depth, and fault height, respectively. The proposed overall PCI is made up of 40% cracking index, 40% ride index, and 20% faulting index for portland cement concrete pavements and 40% cracking index, 40% ride index, and 20% rutting index for asphalt concrete pavements. The proposed condition index was compared with the current PCI and, in general, was found to offer fairly good correlation.