Climate Impacts and Adaptations on Roads in Northern Canada

Canada’s 900,000 km of roads covers a wide diversity of geography, activities, features and climate, with climate being characterized by 10 zones. Two of these zones cover the continuous and discontinuous areas of permafrost, but all have been considered in estimating the effects of climate change, in terms of increasing temperatures, on factors including freeze-thaw cycles, flooding and washouts, slope failures, thermal degradation, precipitation and icing. In turn, the expected outcomes of these factors on paved, gravel and snow and ice roads deterioration have been estimated. The outcomes range from minimal to definitively negative in terms of accelerated deterioration and increased costs. Some potential adaptive measures have been identified, and a case illustration of the effect of a climatic zone changing from wet, high freeze to wet low freeze with increased freeze thaw cycles is provided. This could well be the case for a northern roads situation of increasing temperatures, and the results of the case illustration indicate that for paved roads service life could be reduced by 2 to 5 years. Finally, suggestions for research on the effects of climate change on northern roads are provided, with the highest priorities related to increasing temperatures and increased freeze-thaw cycles.