Sustainable Highway Development in a National Park

Sustainable highway-engineering improvements have been developed or adopted to mitigate the unique environmental impact that highways and roads have in Canadian Rocky Mountain National Parks, which are also World Heritage Sites. Three levels of sustainable highway development are presented. The first is the reconstruction or rehabilitation of park roads. Examples are presented from several national parks in which parkways and low-volume roads were reconstructed or repaired in ways that reduced impacts. The second is the development of the passing-lane system on the Trans-Canada Highway in the Rocky Mountain National Parks. The passing-lane system has extended the design service life of the two-lane highway by approximately 15 years while maintaining an acceptable level of service. The third example is the twinning of 18.6 km of the Trans-Canada Highway, which represents a logical next step in a program of sequential twinning following the passing-lane phase. Discussion includes the ways in which highway-engineering improvements were developed to address and mitigate numerous potential project impacts that were identified during environmental assessment. Included in the environmental mitigations were a series of measures such as fencing, animal-crossing structures, and underpasses to address wildlife movement, biodiversity, and mortality. Stream, terrain, and vegetation disturbance-minimization techniques also were applied. Research has found that the mitigation measures have been effective in reducing wildlife–vehicle collisions by as much as 97 percent.