US Bridges

Irr# County RD 334 over Allison Ditch

Fair

La Plata County, Colorado · 2 MI N of SH 151 · Structure no. 067033402.0037A

Built
1989
36 years old
Condition
Fair
inspected October 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
26 ft
1 main span
Daily traffic
210
2022 count
Owner
County
County Highway Agency

About this bridge

Irr# County RD 334 over Allison Ditch is a steel stringer/multi-beam or girder carrying Irr# County RD 334 over Allison Ditch in La Plata County, Colorado. It was built in 1989, so it is 36 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 210 vehicles a day, roughly 2% of them trucks, projected to reach 247 by 2042. The structure is 26 ft (8 m) long and 32 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
Location2 MI N of SH 151
RouteCounty Highway 0
CountyLa Plata County
StateColorado
Coordinates37.13036, -107.55067
Functional classRural Minor Collector

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck9 ExcellentNo problems noted.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating56 US tons
Inventory rating33.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckCorrugated steel
Main spans1
Design loadHS 20
Structure length26 ft (8 m)
Longest span24 ft (7.3 m)
Deck width32 ft (9.8 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic210 (2022)
Projected traffic247 by 2042
Trucks2%
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 1989, making it 36 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 210 vehicles per day (2022 count), of which roughly 2% are trucks.

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

The structure is 26 ft (8 m) long with a longest span of 24 ft (7.3 m) and a deck 32 ft wide.

Who owns Irr# County RD 334 over Allison Ditch?

It is owned by the County Highway Agency.