Structure F-12-BP · Summit County, CO

SH 9 Ml over Blue River

Carries SH 9 Ml over Blue River, In Silverthorne.

Overall conditionFair

Set by its lowest-rated component: Culvert at 6 of 9.

How ratings work
Culvertsets the rating6/9 · Satisfactory
Channelnot part of overall8/9 · Very Good
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
CAR · 15 FT69 FT ACROSS25 FT0ELEVATION · LENGTHS TO SCALE
Culvert 6/9

A culvert 69 ft across with 5 openings. Lengths and the car on the deck are drawn to the same scale. Each part is colored by its latest inspection rating. The inventory records lengths but not heights, so those are drawn as typical for a culvert.

Built198244 years old
Length68.9 ft21 m
Daily traffic20,000counted 2020
Last inspectedAugust 2023every 24 months

Location

StateColorado
CountySummit
LocationIn Silverthorne
CarriesSH 9 Ml
CrossesBlue River
Coordinates39.62936, -106.07146

Physical Characteristics

MaterialConcrete
DesignCulvert
Total Length68.9 ft (21 m)
Max Span14.1 ft (4.3 m)
Deck Width138.1 ft (42.1 m)
Deck Area884.1 sq m
Main Spans5
Year Built1982

Traffic

Avg Daily Traffic20,000 (2020)
Truck Traffic6%
Lanes On Bridge5

Inspection & Ownership

Last InspectionAugust 2023
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour Critical8 — Stable, low risk
Structure NumberF-12-BP

How Bridge Ratings Work

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."

0Failed
1Imminent failure
2Critical
3Serious
4Poor
5Fair
6Satisfactory
7Good
8Very good
9Excellent
Good · lowest component 7–9
Fair · lowest component 5–6
Poor · lowest component 0–4

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.

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