Bridges and Culverts

The County maintains a diverse transportation network to provide safe and effective means to keep our communities moving and connected. This network includes bridges and structural culverts which help provide continuous efficient movement of traffic.

Bridges and structural culverts are categorized into three components, based on differing life spans and maintenance strategies; bridges (including pedestrian bridges), structural culverts with a span of 3 meters or greater, and guide rails related to the structure approaches that protect road users from underlying and/or roadside hazards.

Inventory

Due to the varying structure types and material, the replacement costs are not easily defined as a value per square meter of bridge/culvert deck area. Replacement costs were provided within the 2024 Bridge Needs Study. The replacement cost valuation for guide rails is based on current tender prices, where available.

The County continues to experience tender results that are below the replacement cost estimates provided through the 2024 Bridge Needs Study. The replacement costs noted in the study are intended to represent the full costs of replacing the structure and are intended to capture the costs associated with the size or type of structure that would be built, which may include an expansion of structure size to accommodate active transportation solutions. Staff will work with the consultants on methodology used in determining replacement costs to achieve closer alignment with recent tender results.

Condition

The condition assessment approach utilizes a combination of physical assessments, asset attributes, such as material and sizing, and established anticipated useful lives. 

The MTO has established a goal of maintaining 85% of their structures in good condition, with a BCI greater than 70. Of the County’s 165 structures, 98 (59%) have a projected BCI at 70 or greater as of December 31, 2024. Another 21 structures (13%) have a projected BCI between 68 and 70. 

Key Performance

It is intended that all bridges and structural culverts will be maintained, rehabilitated, and replaced to perform the same function and manage the same traffic volumes and loads as they are currently designed to do. While the County can control development within its boundaries, activities occurring in surrounding areas can impact use of the County’s structures and thus the level of service achieved.

Proposed Levels of Service Review

Information on the scenarios reviewed is contained within the AMP document. As the design and construct process for structures occurs over a multi-year period and the County aligns upcoming work in the asset management software with recommendations from the Bridge Needs Study, the lifecycle needs under all scenarios are consistent for the majority of the first decade. 

It is important to note that under each scenario a bottleneck occurs in approximately 40 years as a significant number of structures are anticipated to require lifecycle activities. Staff do not anticipate having the internal resources available to complete all activities the year they are due and therefore we see a decline in the condition rating under each scenario. Projected lifecycle needs in the bottleneck period may naturally be deferred based on regular updates to condition information as assets progress through their lifecycle.

Based on the analysis, staff are recommending Scenario D. The proposed level of service is maintained at an average BCI of 70, which results in an annual investment level of approximately $6.7 million. This recommendation is in line with the 2025 Budget Survey responses where 71% of respondents indicated that the service level related to County roads and bridges should be maintained.

Funding Gap Analysis

Planned Investment Level
Staff are recommending holding the OCIF contribution towards this portfolio to $2.5 million over the period. While this is higher than the current contribution in 2025, it is lower than the 2025 budgeted projections for future years. It is further proposed that the annual contribution to the Bridges and Structural Culverts reserve remain static at $2.64 million through 2028. Inflationary increases equal to 2.5% are then added from 2029 through 2035, aligning with the anticipated inflationary increase in the required investment. 

Proposed Investment Change
Despite the proposed service level deficit, staff are not proposing any additional investment changes for the 2026 budget. Further information on the replacement cost disparity is required before an increase is recommended. This investment level hold is not projected to result in any reductions in the level of service or increase in risk in the near-term. An increase of approximately 2% or $60,000 has been shown for 2029 through 2035. 

Comparison of required investment to proposed investment (millions)