US Bridges

Irr# County RD 334 over Allison Ditch

Fair

La Plata County, Colorado · .5 MI E of CR 336 · Structure no. 067033403.6039A

Built
1997
28 years old
Condition
Fair
inspected October 2024
Type
Slab
Prestressed Concrete
Length
25 ft
1 main span
Daily traffic
86
2022 count
Owner
County
County Highway Agency

About this bridge

Irr# County RD 334 over Allison Ditch is a prestressed concrete slab carrying Irr# County RD 334 over Allison Ditch in La Plata County, Colorado. It was built in 1997, so it is 28 years old, younger 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 6 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 86 vehicles a day, projected to reach 102 by 2042. The structure is 25 ft (7.6 m) long and 24 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesIrr# County RD 334
CrossesAllison Ditch
Location.5 MI E of CR 336
RouteCounty Highway 0
CountyLa Plata County
StateColorado
Coordinates37.13866, -107.56869
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure9 ExcellentNo problems noted.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating89.7 US tons
Inventory rating55.6 US tons

Structure

Structure typeSlab
MaterialPrestressed Concrete
DeckOther
Main spans1
Design loadHS 20
Structure length25 ft (7.6 m)
Longest span23 ft (6.9 m)
Deck width24 ft (7.3 m)
Roadway width23 ft (7.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic86 (2022)
Projected traffic102 by 2042
Trucks0%
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—
NavigationNo navigation control on waterway

Frequently asked questions

When was Irr# County RD 334 over Allison Ditch built?

It was built in 1997, making it 28 years old in 2025.

What condition is Irr# County RD 334 over Allison 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 October 2024.

How much traffic does Irr# County RD 334 over Allison Ditch carry?

About 86 vehicles per day (2022 count).

How long is Irr# County RD 334 over Allison Ditch?

The structure is 25 ft (7.6 m) long with a longest span of 23 ft (6.9 m) and a deck 24 ft wide.

Who owns Irr# County RD 334 over Allison Ditch?

It is owned by the County Highway Agency.