US Bridges

Coburg Road over Overflow Channel

Fair

Lane County, Oregon · At Armitage State Park · Structure no. 15139B150000477

Built
1985
40 years old
Condition
Fair
inspected May 2023
Type
Slab
Prestressed Concrete
Length
191 ft
4 main spans
Daily traffic
10,265
2020 count
Owner
County
County Highway Agency

About this bridge

Coburg Road over Overflow Channel is a prestressed concrete slab carrying Coburg Road over Overflow Channel in Lane County, Oregon. It was built in 1985, so it is 40 years old, younger than the Oregon average of 49.9 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 10,265 vehicles a day, roughly 15% of them trucks, projected to reach 15,613 by 2025. The structure is 191 ft (58.2 m) long and 44 ft wide. If it were closed, the detour would be 11.2 mi (18 km).

Location

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CarriesCoburg Road
CrossesOverflow Channel
LocationAt Armitage State Park
RouteCounty Highway A0465
CountyLane County
StateOregon
Coordinates44.11072, -123.04813
Functional classUrban 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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation3: Basically intolerable, requiring high priority of corrective action
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating19 US tons
Inventory rating14.7 US tons

Structure

Structure typeSlab
MaterialPrestressed Concrete
DeckOther
Main spans4
Design loadHS 20
Structure length191 ft (58.2 m)
Longest span48 ft (14.6 m)
Deck width44 ft (13.4 m)
Roadway width41 ft (12.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic10,265 (2020)
Projected traffic15,613 by 2025
Trucks15%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesRelief for waterway
Detour if closed11.2 mi (18 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 Coburg Road over Overflow Channel built?

It was built in 1985, making it 40 years old in 2025.

What condition is Coburg Road over Overflow Channel 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 May 2023.

How much traffic does Coburg Road over Overflow Channel carry?

About 10,265 vehicles per day (2020 count), of which roughly 15% are trucks.

How long is Coburg Road over Overflow Channel?

The structure is 191 ft (58.2 m) long with a longest span of 48 ft (14.6 m) and a deck 44 ft wide.

Who owns Coburg Road over Overflow Channel?

It is owned by the County Highway Agency.