Sustainability metrics of flexible pavement preservation and rehabilitation in Canada

The Ministry of Transportation Ontario (MTO) is committed to maintaining the provincial transportation infrastructure in a sustainable manner. One way to achieve pavement sustainability is through the combined use of environmentally sound pavement preservation and in-situ pavement recycling strategies. Pavement preservation is the use of proactive, planned strategies that extend the life of the pavement, providing a cost effective solution for asset management. In-place pavement recycling is a pavement rehabilitation strategy that reuses 100% of the existing roadway materials, conserving non-renewable resources, eliminating disposal costs, and reducing environmental impacts. This paper outlines the various pavement preservation and in-place recycling strategies utilized in Canada to achieve sustainability. Pavement sustainability is quantified by comparing the energy consumption and Greenhouse Gas (GHG) emissions generated by the various pavement rehabilitation strategies using the PaLATE software. The results indicate that pavement preservation and in-place recycling strategies are cost competitive and provide a significant reduction in energy use, aggregate consumption, and GHG emissions when compared to traditional rehabilitation treatments. Detailed discussion on these technologies and their environmental impacts are presented, as well as a 10 years historical perspective of the Ministry's pavement preservation and in-place recycling program.