Development of an expert system for sustainable pavement preservation strategies (ES2P2S)

Pavement preservation is one of the most cost effective, environmentally and socially sustainable ways to manage deteriorating roadway systems when applied in a proper way. However, the current practice does not consider a long-term sustainability strategy and lacks the systematic approach of establishing the pavement preservation strategy considering sustainability. The principal objective of this study was to develop an expert system for the evaluation of various pavement strategies by incorporating economic, environmental and social sustainability aspects into decision-making.;Sustainable pavement preservation was defined to be able to maintain the roadway in good condition (engineering), be cost effective (economic) and reduce energy consumption and global warming potential (GWP) emissions (environmental) and minimize the impact on water quality and on noise level (social) during the entire life cycle of the pavement. The cost effectiveness was measured by the ratio of user benefit to maintenance cost. The modified pavement Life-Cycle Assessment Tool for Environmental and Economic Effects (PaLATE) was used to assess the energy consumption and GWP. Water quality and noise impacts were quantified by in-depth studies and rated by an ordinal categorical values such as moderate or good.;Based on the proposed framework of sustainability, a user-friendly expert system named the Expert System for Sustainable Pavement Preservation Strategy (ES2P2S) was developed using the Visual Basic Application (VBA). ES2P2S is capable of quantifying the impacts of multiple pavement preservation strategies in terms of economic, environmental and social perspectives. Multiple performance criteria analysis in ES2P2S also allows for the evaluation of the overall sustainability of pavement preservation strategies. The results of ES2P2S analysis of an actual project showed that micro surfacing could save 63.1% of the cost, consume only 11.1% of energy, and emit 11.2% of GWP compared with the thin hot mix asphalt (HMA) overlay.;The expert system developed was able to successfully evaluate the overall sustainability of strategies. Thus, ES2P 2S can be used to assist pavement preservation decision makers in understanding how the sustainability concept can be integrated into pavement preservation decision-making. It would result in maintaining a sound roadway system in a sustainable and economical way.