Development of overall pavement condition index for maintenance strategy selection for Indian highways

Punctually and appropriate maintenance of pavement black top surface using suitable material and method is significant for the preservation of road assets and to serve the intended purpose. An adequate maintenance management system that would be useful to highway agencies in regularly planning pavement maintenance strategies to ensure the minimal maintenance fund is used rationally. The target of this paper is to develop a hypothetic overall pavement condition index (OPCI) for the maintenance strategy selection for Indian Highways, exclusively for flexible pavements. This index incorporates salient indicators as distress, structural capacity, roughness and skid resistance. The distress index has been computed considering the maximum allowable extent principle. Multiplicative Index Approach was applied to develop OPCI. An expert opinion survey was conducted to evaluate the weightage for each indicator using the relative impact on pavement condition. The results reveal that the weight factor is 0.6 for structure capacity, 0.5 for roughness and 0.15 for skid resistance which is lower than the distress weight factor. The relative importance that should be given to each indicator are calculated to be 80% for distresses, 10% for structural capacity, 8% for roughness and 2% for skid resistance. The combined distress pavement condition index infests in almost one higher rating scale than PCI whereas OPCI is 21% lower than the PCI. This indicates the requirement of a conservative maintenance alternative. However, a condition indicator that consists of multiple indices is much more important in identifying suitable maintenance alternative approaches to fully restore the structural integrity and riding quality of the pavement.