Structure LONG-AIRRD-SVRD · Boulder County, CO

Airport Road over St. Vrain River Overflow

Carries Airport Road over St. Vrain River Overflow, 0.2 Mi N Of ST Vrain RD.

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 FT44 FT ACROSS25 FT0ELEVATION · LENGTHS TO SCALE
Culvert 6/9

A culvert 44 ft across with 3 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.

Built200620 years old
Length43.6 ft13.3 m
Daily traffic13,131counted 2023
Last inspectedJanuary 2025every 24 months

Location

StateColorado
CountyBoulder
Location0.2 Mi N Of ST Vrain RD
CarriesAirport Road
CrossesSt. Vrain River Overflow
Coordinates40.17008, -105.15464

Physical Characteristics

MaterialConcrete
DesignCulvert
Total Length43.6 ft (13.3 m)
Max Span14.1 ft (4.3 m)
Deck Width92.2 ft (28.1 m)
Deck Area373.7 sq m
Main Spans3
Year Built2006

Traffic

Avg Daily Traffic13,131 (2023)
Truck Traffic3%
Lanes On Bridge5

Inspection & Ownership

Last InspectionJanuary 2025
Inspection FrequencyEvery 24 months
OwnerCity/Municipal Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour Critical8 — Stable, low risk
Structure NumberLONG-AIRRD-SVRD

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.

Nearby Bridges