US Bridges

County Road 901 over Boulder Creek

Fair

Boulder County, Colorado · 0.3 MI N of ST HWY 52 · Structure no. BC-901-11.6-BO

Built
1976
49 years old
Condition
Fair
inspected February 2025
Type
Tee Beam
Prestressed Concrete
Length
126 ft
2 main spans
Daily traffic
6,549
2023 count
Owner
County
County Highway Agency

About this bridge

County Road 901 over Boulder Creek is a prestressed concrete tee beam carrying County Road 901 over Boulder Creek in Boulder County, Colorado. It was built in 1976, so it is 49 years old, older than the Colorado average of 42.2 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 5 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 6,549 vehicles a day, roughly 20% of them trucks, projected to reach 7,859 by 2043. The structure is 126 ft (38.5 m) long and 39 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

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CarriesCounty Road 901
CrossesBoulder Creek
Location0.3 MI N of ST HWY 52
RouteCounty Highway 0
CountyBoulder County
StateColorado
Coordinates40.0918, -105.05538
Functional classRural Minor Arterial

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionFebruary 2025
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating40 US tons
Inventory rating36 US tons

Structure

Structure typeTee Beam
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20
Structure length126 ft (38.5 m)
Longest span62 ft (18.8 m)
Deck width39 ft (11.8 m)
Roadway width36 ft (11 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic6,549 (2023)
Projected traffic7,859 by 2043
Trucks20%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was County Road 901 over Boulder Creek built?

It was built in 1976, making it 49 years old in 2025.

What condition is County Road 901 over Boulder Creek in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in February 2025.

How much traffic does County Road 901 over Boulder Creek carry?

About 6,549 vehicles per day (2023 count), of which roughly 20% are trucks.

How long is County Road 901 over Boulder Creek?

The structure is 126 ft (38.5 m) long with a longest span of 62 ft (18.8 m) and a deck 39 ft wide.

Who owns County Road 901 over Boulder Creek?

It is owned by the County Highway Agency.