Designing the Inuvik Tuktoyaktuk Highway
In the face of climatic warming evident in Canada’s northern territories, a reliable transportation system is key to major contributions to Canada’s national economy through sustainable and efficient development of resources and improved access to education, health care, and employment opportunities for Canada’s most vulnerable people.
The federal government has considered an all-weather highway through the valley and delta of the Mackenzie River to the Arctic Coast a strategic priority for Canada since the late 1950s. The final link to connect Canada from coast to coast to coast, this highway (more than 140 kilometers from Inuvik to Tuktoyaktuk) provides a reliable transportation system for the people of the Inuvialuit Settlement Region.
Through an indigenous peoples joint venture partnership, Kiggiak-EBA Consulting Ltd., Tetra Tech completed work with the Department of Transportation, Government of the Northwest Territories, the Town of Inuvik, the Hamlet of Tuktoyaktuk, and a joint venture of indigenous contractors—EGT Northwind Ltd.—to design the highway and prepare the documents that needed to be submitted to regulators to gain approval for construction. The designs and documents produced also were used to lobby the federal government for the funding for construction.
In March 2013 the Inuvik Tuktoyaktuk Highway received environmental approval and funding approval from the federal and territorial governments. Tetra Tech worked with EGT Northwind Ltd. as part of the design-build team, completing detailed designs, conducting geotechnical investigations, and preparing construction specifications. Construction commenced in January 2014 and opened in the fall of 2017. Tetra Tech played an important role in delivery of the highway by providing engineering expertise and quality control services to EGT Northwind Ltd. during construction.
The Inuvik Tuktoyaktuk Highway traverses particularly challenging, ice-rich, thaw-sensitive permafrost terrain. The design and construction approach required a movement away from traditional engineering practices to maintain the overall integrity of the roadway and drainage structures while accounting for permafrost thaw due to climate change.
The preliminary engineering and design steps incorporated ground temperature monitoring for baseline conditions; ground-penetrating radar used at select locations to confirm the presence of massive ice; ground thermal analysis to predict freeze and thaw in the embankment structure; slope stability analysis in frozen, but unstable, ground; and other techniques. The design and construction approach in general includes 100 percent fill (no cut) and an adaptive approach to risk management and climate change.