The Colorado Department of Transportation (CDOT) has released its 2024 routine inspection report for the Castle Creek Bridge on Colorado Highway 82, confirming that the bridge can continue to be used safely and without weight restrictions.

Built in 1961, the bridge received an overall condition rating of “Satisfactory,” consistent with previous reviews.

The inspection, completed Sept. 25, is part of a regular two-year cycle for CDOT bridges across the state. The next routine inspection of the almost 64-year-old structure is scheduled for September 2026.

Detailed inspection results

Bridge inspections are divided into three components: the deck (riding surface), the superstructure (beams that support the deck), and the substructure (columns and foundations).

Each component of the Castle Creek Bridge was rated “satisfactory,” with inspectors noting typical signs of aging but no immediate structural risks.

• Deck: Inspectors noted moderate cracking with rust spots on approximately 8% of the deck surface.

• Superstructure: Moderate corrosion was observed on less than 10% of the steel beams. Of the bridge’s 7,776 tack welds, 53 were partially cracked, although these welds, used for alignment during construction, have no structural significance.

• Substructure: Defects included cracks, chips and some areas of concrete separation. Several areas have already been repaired without losing structural integrity.

According to CDOT, the bridge’s condition has been stable for many years and no significant deterioration is expected before the next inspection cycle.

Understanding a “Fair” Rating

According to the National Bridge Inspection Standards (NBIS), bridges are rated on a scale of 0 (fail) to 9 (excellent). A “Satisfactory” rating, which corresponds to a rating of 5 or 6, means the structure is fine but may have minor problems such as cracks or corrosion. Bridges rated this way require regular maintenance to ensure their longevity, but do not require immediate repair.

In contrast, a “Poor” rating (4 or less) indicates advanced deterioration that may require extensive rehabilitation or replacement. However, such bridges remain safe unless immediate action is required.

The Castle Creek Bridge underwent extensive maintenance in September 2023. This included the installation of a new approach slab, a bridge extension device to address thermal movement, and updated sidewalk and curb gutter features.

These improvements aim to reduce water-related damage by preventing leaks in the bridge’s structural components.

CDOT conducts visual inspections of most bridges and uses additional tools and technology to address specific concerns as needed. Routine inspections help monitor aging infrastructure and determine if adjustments to inspection frequency are needed.

Currently, the Castle Creek Bridge continues to adhere to the standard 24-month schedule, reflecting confidence in its structural stability.

CDOT emphasizes that while aging infrastructure continues to pose challenges, bridges like Castle Creek are safe for public use and are proactively maintained to extend their lifespan.