US Bridges

Willamette Drive over Slough

Good

Lane County, Oregon · 020 MI E Junction City · Structure no. 39C304311200102

Built
1992
33 years old
Condition
Good
inspected July 2024
Type
Slab
Prestressed Concrete
Length
71 ft
1 main span
Daily traffic
215
2020 count
Owner
County
County Highway Agency

About this bridge

Willamette Drive over Slough is a prestressed concrete slab carrying Willamette Drive over Slough in Lane County, Oregon. It was built in 1992, so it is 33 years old, younger than the Oregon average of 49.9 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 215 vehicles a day, projected to reach 246 by 2025. The structure is 71 ft (21.6 m) long and 24 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

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CarriesWillamette Drive
CrossesSlough
Location020 MI E Junction City
RouteCounty Highway C3112
CountyLane County
StateOregon
Coordinates44.2311, -123.17281
Functional classRural Local

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJuly 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation7: Better than present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating55.7 US tons
Inventory rating42.9 US tons

Structure

Structure typeSlab
MaterialPrestressed Concrete
DeckOther
Main spans1
Design loadHS 25 or greater
Structure length71 ft (21.6 m)
Longest span70 ft (21.3 m)
Deck width24 ft (7.3 m)
Roadway width23 ft (7.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic215 (2020)
Projected traffic246 by 2025
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed123.7 mi (199 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$472,000
NavigationNo navigation control on waterway

Frequently asked questions

When was Willamette Drive over Slough built?

It was built in 1992, making it 33 years old in 2025.

What condition is Willamette Drive over Slough in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in July 2024.

How much traffic does Willamette Drive over Slough carry?

About 215 vehicles per day (2020 count).

How long is Willamette Drive over Slough?

The structure is 71 ft (21.6 m) long with a longest span of 70 ft (21.3 m) and a deck 24 ft wide.

Who owns Willamette Drive over Slough?

It is owned by the County Highway Agency.