Banff National Park of Canada

Park Management

Trans-Canada Highway Twinning

The Banff Wildlife Crossings Project Report, 2002

TRANS-CANADA HIGHWAY TWINNING

Twinning the highway involved upgrading the highway from two lanes to four lanes as seen in the following photo

Two lanes - ca 1955 © Parks Canada / Bruno Engler

Four lanes - 1998 © Parks Canada

Since the mid-1970s, collisions between vehicles and large mammals on the TCH have been a concern of Parks Canada. Increasing traffic and vehicle collisions with wildlife during the 1980s prompted Parks Canada to upgrade the first 27 km of highway in Banff to four lanes (Phase 1 and 2; map below). To reduce the number of wildlife-vehicle collisions, a 2.4 m high ungulate-proof fence was installed along both sides of the twinned highway. To minimize the disruption of wildlife movements, wildlife underpasses were incorporated into the highway design. In the mid-1990s, similar concerns regarding increasing traffic demands and maintaining park ecological integrity prompted Parks Canada to widen an additional 18 km to four lanes (Phase 3A; map below), complete with fencing, wildlife underpasses and overpasses.

Overview of all the phases (1, 2, 3A and 3B) of the Trans-Canada Highway, Banff National Park © Parks Canada

Mitigation Measures

Wildlife crossing structures

Five different types of wildlife crossing structures are found in Banff:

(1) creek bridge underpasses (3 m high x 11 m wide expanded bridges that span creeks and rivers), © Tony Clevenger

(2) elliptical, metal culvert underpasses (4 m high x 7 m wide), © Tony Clevenger

(3) prefabricated concrete box underpasses (2.5 m x 3.0 m), © Tony Clevenger

(4)open-span concrete bridge underpass (3 m high x 11 m wide), and © Tony Clevenger

(5) 50-m wide wildlife overpasses. © Tony Clevenger

The two 50-m wide wildlife overpasses were the first of this magnitude to be built in North America. Three considerations were taken into account for overpass placement; preferred wildlife crossing points, favorable terrain configuration for engineering and construction considerations, and driver safety requirements. Earth berms were built on the overpasses to reduce disturbance (noise, lights) from highway traffic.

Earth berms on overpass © Tony Clevenger

Fencing and one-way gates

2.4 m high wildlife fence © Tony Clevenger

The mitigated section of TCH (45 km) is bordered on both sides with a 2.4 m high wildlife fence, to help keep wildlife off the right-of-way and direct wildlife to the crossing structures. The phase 1 & 2 fence is not buried as it was primarily designed to keep ungulates off the road and not coyotes and wolves who can dig under the fence. However, the phase 3A fence is buried, having a 1.5-m apron that extends into the ground at a 45-degree angle away from the fence.

Wildlife fence with apron © Tony Clevenger

One-way gates were installed along the fence on phase 1 & 2 to provide an escape for animals that have entered into the highway right-of-way.

One way Gate © Tony Clevenger

Where fencing intersects roads leading to the highway, Texas gates have been placed in the road to keep wildlife from entering the right-of-ways.

Texas Gate © Tony Clevenger

Double-door swing gates and pedestrian gates are used to allow human access beyond the highway right-of-way.

Double door swing gate © Tony Clevenger

Pedestrian Gate © Tony Clevenger

< Previous Page | Table of Contents | Next Page >