Centreline road mad river bridge replacement
The County of Simcoe is planning the replacement of the Mad River Bridge on Centre Line Road, located approximately 0.4 km north of Tosorontio Sideroad 32, west of Glencairn. The bridge carries Centre Line Road over the Mad River and is located on the boundary between the Townships of Clearview and Adjala-Tosorontio.
The existing bridge was originally constructed circa 1920 and is understood to have undergone a major superstructure replacement around 1950. Recent inspections have identified deterioration in the existing bridge deck and steel girders, including corrosion, section loss, cracking, potholes in the asphalt wearing surface, and deterioration of the underlying timber deck. The 2024 OSIM inspection assigned the bridge a Bridge Condition Index (BCI) of 58, which falls within the “Poor” category, and recommended major rehabilitation or full replacement. Given the age and condition of the structure, the County is proceeding with a full bridge replacement.
The proposed replacement will include a new single-span bridge using precast concrete box girders, supported by new cast-in-place concrete abutments on helical pile foundations. The new bridge will provide a wider roadway platform with improved lane and shoulder widths, new concrete curbs, a three-tube railing system, new guide rail connections, and related road approach improvements. The project will also include erosion protection and embankment stabilization works as required near the southwest approach to help protect the roadway platform from river-related erosion.
The replacement bridge has been designed to improve existing conditions while balancing constructability, cost, environmental constraints, hydraulic performance, and property impacts. The existing crossing is hydraulically constrained, and the new structure is expected to provide modest improvement in hydraulic performance while generally maintaining the existing roadway profile and navigational clearance.
Timelines (subject to change as project proceeds)
Construction is anticipated to take place this summer with utility relocation taking place in 2026 in May through June and bridge construction starting in July and anticipated to be completed in December 2026.
impacts to drivers and neighbours
A full closure of Centre Line Road at the Mad River Bridge is anticipated during construction.
Traffic will be redirected using a signed detour route. The preliminary detour identified in the design report uses Centre Line Road, Mulmur Nottawasaga Townline, Airport Road, and Nottawasaga Sideroad 3 & 4. This detour is approximately 9.2 km long.
Residents and road users should expect construction activity near the bridge, including bridge removal, foundation work, new bridge construction, road approach reconstruction, guide rail installation, utility coordination, and restoration. Access for emergency services, local residents, and affected property owners will be reviewed as part of construction planning.
County’s Commitment and Experience
The County of Simcoe continues to invest in keep the infrastructure in a state of good repair.
We appreciate the public’s patience as we ensure that work on this significant improvement is being completed safely and properly and according to the County’s requirements