Incorporating GHG Mitigation into Ontario Highway Pavement Engineering Practices

Abstract

Greenhouse Gas (GHG) emissions are main concern for many national and international agencies. Increased human activities and growth in all sectors are affecting our society in a positive way but also putting our future generations at risk by affecting the environment through increases in GHG emissions. The transportation sector has been shown to be the second largest contributor to Canada’s total GHG emissions with Ontario being the second largest contributor of GHG emissions among all the provinces of Canada. In 2016, the Ministry of Transportation of Ontario (MTO) published its strategy and commitment to minimize the GHG emissions by 80% below the 1990 levels by 2050. In Ontario, the transportation sector accounts for almost 35% of GHG emissions. In addition to increased emissions, increased traffic volumes and loads are putting extra demand on the existing pavement system. Canada faces many challenges in maintaining road transportation infrastructure as the roads are aging and there are limited funds available for maintenance and repairs. Traffic volumes and vehicle loads continue to increase, putting even more demand on the already stressed pavement system in major metropolitan areas and resulting in serious congestion problems. These challenges force road agencies to form innovative ways to sustain and develop new transportation infrastructure. As our highway infrastructure ages, the transportation industry needs to find alternatives or strategies of building, maintaining and reconstructing road infrastructure that is cost effective and minimizes the environmental impact. This research is to identify strategies that are currently used in the road construction industry by different jurisdictions which may show promise for usage in Canada. This research quantifies the benefits of adopting new strategies into Ontario’s transportation infrastructure practice as case studies are evaluated for their ability to mitigate the GHG emissions in the transportation sector. iv Four strategies were selected and studied based on their feasibility in term of costs, level of adaptation and industry’s existing capacity to practice in Ontario. The strategies are Moveable Barrier System, Accelerate construction, Two lift concrete pavement construction and High Modulus Asphalt pavement design Case studies focused on improving the traffic congestion, rapid construction practices, improved design standards, modified construction practices, reducing the consumption of virgin aggregates and allowing the use of more locally available material. GHG emission results and associated impacts are calculated and compared between conventional methods and selected innovations to evaluate the feasibility of adopting the strategies for cost, internal resources and existing capacity in Ontario’s industry. The Athena software tool was used to perform a life cycle analysis and the comparative studies between the conventional methods and new innovative strategies. Overall the results using Athena software as well as manual calculations shows that selected new strategies helps to reduce the GHG emissions from the transportation construction practices.