Inuvik Tuktoyaktuk Highway

The first all-weather road to the Canadian Arctic Coast, connecting Canada’s highway network from coast to coast to coast.

The Inuvik Tuktoyaktuk Highway— engineered collaboratively by Tetra Tech and Stantec — marked the first connection of the rest of Canada’s highway system to the Arctic Ocean, which fulfilled a strategic mandate of the governments of the Northwest Territories and Canada dating back to the 1960s.

This was the first public highway in Canada in which roads & bridges face a thaw sensitive, continuous permafrost environment. This presented challenges including how to cause the permafrost to aggrade into the base of the embankment to ensure a stable foundation; and the development of methodologies for placement of embankment and culvert backfill in frigid winter conditions with variable silty borrow material.

Additionally, the project required the design of bridge foundations using adfreeze piles that needed both to consider creep considerations and measures to ensure a frozen soil interface bond should the climate continue to warm.

Maintaining the permafrost regime was key to design & construction. If the permafrost melts, any infrastructure constructed can fail through thaw-settlement of the ice-rich ground and loss of soil strength. To overcome this, the project built an embankment to insulate the underlying permafrost and raise it to the bottom of the road embankment.

This involved calculating the embankment thickness required to insulate the permafrost — considering climate change — to allow the infrastructure to meet its design life and beyond.