US Bridges

ST Vrain Road CR16 over Boulder Feeder Ditch

Fair

Boulder County, Colorado · 0.5 MI E of CO RD 51 · Structure no. BC-16-1.9-ID

Built
1955
70 years old, rebuilt 1983
Condition
Fair
inspected February 2025
Type
Tee Beam
Prestressed Concrete
Length
29 ft
1 main span
Daily traffic
1,009
2023 count
Owner
County
County Highway Agency

About this bridge

ST Vrain Road CR16 over Boulder Feeder Ditch is a prestressed concrete tee beam carrying ST Vrain Road CR16 over Boulder Feeder Ditch in Boulder County, Colorado. It was built in 1955 and reconstructed in 1983, so it is 70 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 1,009 vehicles a day, roughly 8% of them trucks, projected to reach 1,211 by 2043. The structure is 29 ft (8.7 m) long and 29 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesST Vrain Road CR16
CrossesBoulder Feeder Ditch
Location0.5 MI E of CO RD 51
RouteCounty Highway 0
CountyBoulder County
StateColorado
Coordinates40.17427, -105.22695
Functional classRural Local

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionFebruary 2025
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
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 adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating36 US tons
Inventory rating25 US tons

Structure

Structure typeTee Beam
MaterialPrestressed Concrete
DeckOther
Main spans1
Design loadHS 20
Structure length29 ft (8.7 m)
Longest span27 ft (8.1 m)
Deck width29 ft (8.7 m)
Roadway width26 ft (7.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,009 (2023)
Projected traffic1,211 by 2043
Trucks8%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 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 ST Vrain Road CR16 over Boulder Feeder Ditch built?

It was built in 1955, making it 70 years old in 2025. It was reconstructed in 1983.

What condition is ST Vrain Road CR16 over Boulder Feeder Ditch 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 ST Vrain Road CR16 over Boulder Feeder Ditch carry?

About 1,009 vehicles per day (2023 count), of which roughly 8% are trucks.

How long is ST Vrain Road CR16 over Boulder Feeder Ditch?

The structure is 29 ft (8.7 m) long with a longest span of 27 ft (8.1 m) and a deck 29 ft wide.

Who owns ST Vrain Road CR16 over Boulder Feeder Ditch?

It is owned by the County Highway Agency.