US Bridges

E 5th Avenue over Oligarchy Ditch

Fair

Boulder County, Colorado · 0.1 MI East of Fox ST · Structure no. LONG-E5TH-FOX

Built
1970
55 years old
Condition
Fair
inspected January 2025
Type
Culvert
Concrete
Length
22 ft
1 main span
Daily traffic
1,321
2023 count
Owner
City
City or Municipal Highway Agency

About this bridge

E 5th Avenue over Oligarchy Ditch is a concrete culvert carrying E 5th Avenue over Oligarchy Ditch in Boulder County, Colorado. It was built in 1970, so it is 55 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 1,321 vehicles a day, roughly 10% of them trucks, projected to reach 1,586 by 2043. The structure is 22 ft (6.6 m) long and 57 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesE 5th Avenue
CrossesOligarchy Ditch
Location0.1 MI East of Fox ST
RouteCity Street 0
CountyBoulder County
StateColorado
Coordinates40.167, -105.07791
Functional classUrban 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
Channel and channel protection7 GoodSome minor problems.
Culvert5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionJanuary 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 geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating40 US tons
Inventory rating36 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckNot applicable
Main spans1
Design loadUnknown
Structure length22 ft (6.6 m)
Longest span22 ft (6.6 m)
Deck width57 ft (17.5 m)
Roadway width38 ft (11.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,321 (2023)
Projected traffic1,586 by 2043
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal 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 E 5th Avenue over Oligarchy Ditch built?

It was built in 1970, making it 55 years old in 2025.

What condition is E 5th Avenue over Oligarchy 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 January 2025.

How much traffic does E 5th Avenue over Oligarchy Ditch carry?

About 1,321 vehicles per day (2023 count), of which roughly 10% are trucks.

How long is E 5th Avenue over Oligarchy Ditch?

The structure is 22 ft (6.6 m) long with a longest span of 22 ft (6.6 m) and a deck 57 ft wide.

Who owns E 5th Avenue over Oligarchy Ditch?

It is owned by the City or Municipal Highway Agency.