Parks Canada's primary objective is the protection and preservation of the natural environments. The Trans Canada Highway is Canada's primary east-west transportation route from St. John's Newfoundland to Victoria, British Columbia, with the twinning changing a two-lane highway built in the early sixties to a median separated highway with dual east and westbound lanes. The SADT of 13,500+- vehicles has resulted in extensive platooning and a number of serious accidents, thus necessitating the need to continue with the twinning of an 18.2 km section from the Sunshine to Castle Interchange. Banff National Park has been recognized as a World Heritage Site, putting additional emphasis on environmental protection. Spiking of some trees withing the proposed Right of Way to hopefully stop the twinning has received wide media coverage.
With the experience of Phase I and II under out belts we set out to design and construct the 18.2 km of twinning for the Trans Canada Highway from the Sunshine to Castle Mountain Interchange within a montane/sub-alpine environment. The montane valley bottoms present the most productive environment within Banff National Park, which is especially important as winter wildlife range. Unfortunately, the valley bottoms have also seen the highest level of man-made infrastructure. The existing highway alignment is along the lower north facing slopes of the Bow Valley, with the slopes on the south and the Bow River on the north side, thus limiting alignment changes for the twinned highway.