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Yoho National Park / Trans-Canada Highway Twinning

2016-2019 | BC & AB border

The Trans-Canada Highway, completed in 1962, is Canada’s national highway. Due to its importance as a transportation corridor and the increasing traffic demand on the highway, there has been substantial need over the years in upgrading the TCH from its original two-lane form to a four-lane divided highway (“twinning”). The TCH in Yoho National Park was one of the last un-twinned sections of highway in Western Canada.

Located within the Yoho National Park and managed by the Parks Canada Agency, the 6km section in this project was challenging for both roadway users and for the construction of a twinned highway. The existing highway often shared the narrow ecologically sensitive valley bottoms with the CP Railway which severely restricted the usable roadway corridor. Steep unstable mountain slopes, deeply eroded ravines, and river and railway crossings often required the construction of large structures such as retaining walls or bridges.

McElhanney provided comprehensive services to upgrade 6km of highway to a four-lane divided standard, while improving the alignment, safety, and amenities. Our services included engineering design, aerial LiDAR, orthophoto mapping, ground surveys, landscaping design, and construction management. McElhanney’s design carefully took into consideration the environmentally sensitive vegetation and strategically located structures to minimize their impact on rare plants.

McElhanney designed longitudinal fencing and wildlife crossings to facilitate wildlife travel across the four-lane highway. Similar projects adjacent to the area have shown an 80% reduction in collision rates as well as enabling wildlife to migrate to different parts of the parks in their search for feeding and breeding habitat.

The project contained the world’s longest wildlife overpass structure and was featured on numerous Canadian television news stations as well as the Discovery Channel and in local newspapers. While designed by another engineering firm, McElhanney was also engaged by Parks Canada to be the departmental representative for the overpass during construction.

The project was named 2019 Project of the Year by Young Professionals in Transportation International. This award is given annually for a project that had a major impact and where young professionals played a significant role.


Yoho TCH twinning
TCH Yoho
Yoho animal overpass