Lees Avenue Bridge

One of the heaviest bridges to be replaced overnight in North America

First continuous highway bridge in Canada to be entirely rapidly replaced with SPMTs — a technique that is rarely used

  • Existing two-span structure was removed in June 2014 and replaced with a new three-span bridge in September 2014, less than 13 weeks after closure. During this time, the two existing piers were demolished, traffic lanes were relocated, and a new median pier on deep foundations (concrete caissons) was constructed.
  • Removal and replacement structures were each completed overnight in less than 16 hours using self-propelled modular transporters (SPMT)
  • Rather than reducing lanes on a major highway carrying more than 170,000 vehicles per day, traffic disruptions on Highway 417 were limited to two nights, or 30 hours.
  • The new 2,060-t, 87.5-m long, two-span replacement structure involved complex bridge geometry, including curved steel-box girder design and non-standard deck details.
  • 3,500 t of granular material was used to provide an engineered travel route to move the new superstructure 100 m from its staging area to its permanent location, in less than two hours.
  • To move the new structure, eight trains of modular transporters were each equipped with 12 axels, for a total of 384 wheels.
  • Innovative design solutions were combined with excellent teamwork to address complex project challenges, including:
    • curved horizontal alignment
    • 4% cross-fall and 5% average longitudinal grade
    • change of span arrangement
    • re-using existing abutments dictated by severe environmental constraints
    • raising the highway vertical clearance
    • travel path planning with maximum grade limitations


  • detail design
  • preparation of contract documents
  • submission review
  • construction liaison
  • Canadian Institute of Steel Construction, Ontario Regional Steel Design Awards, Award of Excellence, Engineering – Bridge Category, 2015

  • Location: Ottawa, Ontario