Calgary Freeway Protects Wildlife

The network of multi-lane motorways (trails) in Calgary, Canada, has struggled to cope with the city's growth and increasing number of vehicles. The Deerfoot Trail (Highway 2), running north-south through the city, is six-lanes for much of its length, but included a two-lane roadway at the south of the city. UMA Engineering Ltd was awarded the contract to improve the Deerfoot. The project would include an 11km extension, including three interchanges, a river crossing and provision for wildlife to cross the roadway. UMA was lead engineering firm for the entire project, supported by Amec Infrastructure Ltd, Associated Engineering (Alberta) Ltd and Amec Earth and Environmental Ltd. One innovation was a major fork for north bound vehicles exiting onto the Macleod Trail. This eliminated the need for a traditional right exit and reduced the need for one grade separated structure. Shifting the highway alignment avoided interfering with a side channel to the Bow River. Wildlife corridors were constructed along both banks of the river and under the bridge. The bridge construction used 65.3m girders, the longest used in North America. A pond was constructed to catch sediment-laden runoff from the bridge and roadway. The lighting system was designed to minimise light pollution and reduce glare.