Structure BOLD-07-0.59-01 · Boulder County, CO
Carries 30th Street over Empson Ditch, 0.59 Mi N Of Baseline RD.
Set by its lowest-rated component: Deck and Superstructure at 6 of 9.
How ratings work25 ft end to end. Lengths are drawn to scale; at this length a semi-truck would be a speck. Each part is colored by its latest inspection rating. The inventory records lengths but not heights or the layout of the shorter spans, so those are drawn as typical for a tee-beam bridge.
| State | Colorado |
| County | Boulder |
| Location | 0.59 Mi N Of Baseline RD |
| Carries | 30th Street |
| Crosses | Empson Ditch |
| Coordinates | 40.00876, -105.25342 |
| Material | Prestressed Concrete |
| Design | Tee Beam |
| Total Length | 24.9 ft (7.6 m) |
| Max Span | 22.3 ft (6.8 m) |
| Deck Width | 62.0 ft (18.9 m) |
| Deck Area | 143.6 sq m |
| Main Spans | 1 |
| Year Built | 1963 |
| Avg Daily Traffic | 16,733 (2023) |
| Truck Traffic | 2% |
| Lanes On Bridge | 4 |
| Last Inspection | February 2025 |
| Inspection Frequency | Every 24 months |
| Owner | City/Municipal Highway Agency |
| Historical Significance | Bridge is not eligible for the National Register |
| Scour Critical | 5 — Stable for scour |
| Structure Number | BOLD-07-0.59-01 |
Inspectors rate each major part of a bridge (the deck you drive on, the superstructure of beams that holds it up, and the substructure of piers and abutments beneath) on a 0–9 scale. A bridge's overall condition is its lowest of those ratings, so one deteriorated component makes the whole bridge "poor."
A poor rating is not a closure. It means the bridge is flagged for priority repair or replacement; bridges judged unsafe are closed or posted with weight limits. The waterway (channel) rating is reported, but it does not count toward the overall classification.