Projected Impact of Climate Change to Asphalt Pavement Performance in the United States

Robust pavement design must consider a variety of environmental factors and how these may vary over the lifetime of the pavement. Current design practices use historical observed values of climate measures such as temperature, precipitation, and humidity to constrain the average and likely range of future conditions. These conditions are already changing across much of the U.S. and around the world, and projected trends are not adequately reflected in historical data.
Here, we expand on a previous study and quantify the potential impacts of climate change on asphalt pavement across the continental U.S. for a design, representative of typical interstate highways. We consider the implications of three different future climates on pavement performance and lifetime. The three climate futures have incremented levels of global mean temperature (GMT) increase relative to preindustrial levels, two of them in accordance with the Paris climate agreement (+1.5°C, +2°C GMT) and one even higher (+3°C GMT) representing consequences of not adhering to the Paris climate agreement thresholds.
Using an empirical-statistical downscaling model, we develop projections of high-resolution climate variables for 24 weather stations across the U.S. corresponding to a lower and a higher future scenario, using output from 14 global climate models, and disaggregate these into hourly values, which are used as input to the AASHTOware Pavement ME Design™ model.
Results differ from region to region, but projected changes at nearly all locations result in decreased pavement lifetime under current design standards. These results highlight the potential for, and the importance of, quantifying and preparing for the impacts of future change on pavement design.