Illinois Highway Research Study IHR-532 was conducted to develop project-level guidelines for evaluation, rehabilitation selection, and rehabilitation design for existing asphalt concrete–overlaid portland cement concrete (AC/PCC) pavements in Illinois. Use of these guidelines depends on data that are not normally available for network-level analysis. A study was conducted to assess the feasibility of implementing these guidelines in network-level decision making and to assess the effects that implementing these guidelines for selection of rehabilitation methods for existing asphalt-overlaid concrete pavements would have on the overall rehabilitation budget requirements for a district network of Interstate pavements, the overall network condition, and pavement network remaining life. These objectives were met by comparing the IHR-532 rehabilitation strategy (which identifies one or more rehabilitation options) with the Illinois Department of Transportation’s current rehabilitation policy, which is an AC overlay thickness of 83 mm (3.25 in.). This feasibility analysis indicated that the selection of the preferred rehabilitation strategy was strongly related to the type and condition of the existing pavement. It also indicated that the IHR-532 rehabilitation strategy and the single rehabilitation strategy yielded similar networkwide results when compared on the basis of average condition at the end of the analysis period. However, the IHR-532 rehabilitation strategy indicated greater benefit than the single rehabilitation strategy, at any budget level, when compared on the basis of network average remaining life at the end of the analysis period.
