BACKGROUND
Low-volume road bridges (LVRBs) typically carry fewer than 400 vehicles per day but meet the same design requirements as higher-volume bridges. LVRBs may comprise 40% of the bridge inventory in Canadian jurisdictions, and many will require replacement over the next 20 years. Their lower risk profiles and unique characteristics mean that separate design guidelines are warranted.
There is no authoritative reference document for LVRB design. Some jurisdictions have policies for reduced design requirements, standard prefabricated structural systems, and standardized contract documents – but others do not. In addition, some existing policies have been rendered obsolete by post-pandemic market and cost changes.
Safe, sustainable, rapidly implemented and cost-effective LVRB solutions are essential to meeting jurisdictional needs. Practitioners would benefit from a national guideline that synthesizes beneficial practices and integrates lessons learned into consolidated design criteria.
OBJECTIVES
Phase 1
- Synthesize current practices (e.g. design requirements, contracting methods, specifications, standard drawings) in North American jurisdictions for single structures and large bundled replacement projects.
- Define risks for LVRBs by discipline (e.g. geotechnical, hydraulic, roadway alignment, structural) and site factors (e.g. remoteness, access, seasonal use).
- Create a performance-based design framework for LVRBs that outlines clear performance objectives and assessment methods at a level of detail appropriate for LVRB design guidelines.
- Present discipline-specific design criteria tailored to the lower risk profile of LVRBs.
Phase 2
- Examine the current market and identify practical, efficient, low-cost structural systems tailored for LVRBs.
- Outline procurement and contracting approaches for LVRBs, and assess their benefits and disadvantages related to delivery cost and time.
- Develop a consolidated guide to LVRB design in Canada.