By Canada’s extensive road network, coupled with ambitious construction plans, faces a critical environmental challenge. A recent study by the MIT Concrete Sustainability Hub highlights innovative approaches to significantly cut greenhouse gas (GHG) emissions from road construction and maintenance.
Road Construction: A Double-Edged Sword for Canada
Canada boasts over one million kilometers of public roads, with more than 90,000 kilometers constructed between 2017 and 2020 alone. Provinces like Ontario are ramping up efforts to expand high-speed highways near the Greater Toronto Area (GTA). However, only 54% of Canadian roads are in good or very good condition, underscoring the urgent need for repairs and replacements. This dual demand for new roads and maintenance presents a substantial environmental concern, particularly regarding GHG emissions.
MIT’s Groundbreaking Research on GHG Reduction
The MIT Concrete Sustainability Hub’s latest study delves into the environmental impact of road construction materials. Researchers estimated that the annual GHG emissions from all construction materials used in the U.S. pavement network range between 11.9 and 13.3 megatons. To put that into perspective, it’s equivalent to a gasoline-powered passenger vehicle driving about 30 billion miles in a year.
The team didn’t stop at quantifying the problem. They developed a “dynamic model” to assess the future impact of pavement materials demand on GHG emissions. This model takes into account various factors such as annual traffic volume, surface conditions, budget constraints, regional variations in pavement treatment choices, and pavement deterioration.
Projected Emissions Under Business as Usual
If municipalities, regional authorities, and the federal government continue with their current approach to road construction and repair, the MIT team projects a 19.5% increase in GHG emissions from the U.S. pavement network by 2050. This scenario paints a concerning picture of escalating environmental impact tied to infrastructure development.
Ambitious Solutions for a Greener Future
The MIT study offers a beacon of hope with its proposed “ambitious solutions” aimed at achieving significant reductions in cumulative GHG emissions by 2050. These include:
- Carbon Capture: Implementing technologies to capture and store carbon emissions during the production and transportation of construction materials.
- Alternate Material Mixtures: Developing and utilizing low-carbon alternatives to traditional asphalt and concrete.
Concrete Roads: A Promising Alternative
One of the standout recommendations is the increased use of concrete over asphalt. Currently, concrete is used for only six percent of traffic lanes, but the study suggests that ramping up its use could lead to substantial GHG savings. Concrete pavements are stiffer and remain smoother for longer periods, reducing the need for frequent maintenance. This longevity not only lowers maintenance-related emissions but also improves vehicle fuel efficiency by providing a better driving surface.
Andrew Paul Laurent of the MIT Concrete Sustainability Hub emphasizes, “Concrete pavements can offer GHG savings across the whole life cycle as they are stiffer and stay smoother for longer, meaning they require less maintenance and have a lesser impact on the fuel efficiency of vehicles.”
The Role of Grid Decarbonization and Electrification
Achieving carbon neutrality in road construction hinges on broader systemic changes. The effectiveness of the proposed solutions depends heavily on:
- Background Electricity Grid Decarbonization: Transitioning to renewable energy sources for electricity generation to power construction processes.
- Electrification of Transport Systems: Electrifying the transportation of concrete and asphalt ingredients and mixtures to construction sites, thereby reducing emissions from logistics.
Without these foundational shifts, the potential GHG reductions from improved construction practices might not fully materialize.
Practical Implications for Canadian Infrastructure
Canada’s reliance on road infrastructure makes the findings of the MIT study particularly relevant. As Ontario and other provinces continue to promote new road construction, integrating MIT’s recommendations could play a pivotal role in mitigating environmental impact.
- Adopt Low-Carbon Materials: Encourage the use of concrete and other low-carbon alternatives in road construction projects.
- Invest in Carbon Capture Technologies: Support the development and implementation of carbon capture systems within the construction industry.
- Enhance Grid Decarbonization Efforts: Accelerate the transition to renewable energy sources to power construction activities.
- Promote Electrification of Logistics: Facilitate the shift towards electric vehicles for transporting construction materials.
Balancing Development and Sustainability
The challenge lies in balancing the need for robust infrastructure with the imperative to reduce GHG emissions. By adopting a multi-faceted approach that includes material innovation, technological advancements, and systemic changes, Canada can achieve its infrastructure goals while minimizing its environmental footprint.
Potential Benefits:
- Reduced Emissions: Lower GHG emissions from both construction activities and vehicle operations.
- Longer-Lasting Roads: Decreased maintenance frequency leading to cost savings and fewer emissions over time.
- Enhanced Fuel Efficiency: Smoother roads contribute to better fuel economy for vehicles, further reducing emissions.
Collaborative Efforts for Sustainable Infrastructure
Addressing the environmental impact of road construction requires collaboration across various sectors. Governments, construction companies, researchers, and communities must work together to implement the recommended strategies effectively.
Laurent concludes, “The carbon-neutral goal can only be achieved if multiple solutions, including modified material mixtures, are applied simultaneously for reducing, avoiding, and neutralizing the embodied impact.”
As Canada continues to expand and maintain its extensive road network, the insights from the MIT study provide a clear pathway towards sustainability. By embracing innovative materials and technologies, and committing to broader systemic changes, the country can ensure that its infrastructure development aligns with its environmental goals.