Abstract Manager

Highway 40 is part of Alberta’s essential highway network, servicing growing resource traffic south of Grande Prairie, Alberta. The Alberta Government committed to twinning twenty kilometers of the highway south of Grande Prairie, to support the safe and efficient movement of vehicles through a high traffic area, and awarded the design and construction administration to Egis in 2018. A two stage construction commenced in 2021, with construction anticipated to be completed in 2025. The project showcases numerous aspects of public infrastructure engineering, including twinned highway design and construction, bridge structure design and construction, geohazard remediation, utility coordination, intersection improvements and highway illumination requirements.

The traffic composition of the project included peak traffic volumes over 9000 vehicles per day, of which approximately 30% of traffic included tractor trailer units. The corridor often experiences oversized loads that required accommodation throughout the duration of construction.

Key aspects of the project included:

• Nine kilometres of separated carriageways for twinning construction;
• Eleven kilometres of existing grade widening for twinning due to ROW restrictions;
• Coordination of Utilities, including essential supply pipelines to manufacturing centres;
• Construction of a 290m long bridge structure over the Wapiti River;
• Underslung Pedestrian Bridge Structure to encourage active transportation;
• Geotechnical Hazard remediation through toe berms, slope unloading and shear pile walls.

Intersection improvements completed as part of the project included Portland Cement Concrete Pavement wearing surfaces within the town limits and introduction of traffic signals to control traffic movements. Additionally, a dual lane roundabout with an Inscribed Circle Diameter of 81m was constructed to accommodate reactor transports and oversized, overweight log haul vehicles accessing a local pulp and paper mill adjacent to the highway.

The design and construction of the project was challenged by unstable geotechnical sites, bedrock excavations, wetland areas and muskeg deposits that required excavation and replacement with suitable fill materials, or floating of service roads through deeper muskeg deposits. Limited ROW was available through the City of Grande Prairie due to existing infrastructure that could not be relocated.

This paper will discuss the design and construction challenges encountered during the project, as well as the solutions developed to provide a safer highway corridor capable of accommodating a growing resource sector with sufficient capacities for numerous years to come.