US Bridges

South Slough Road over South Slough

Fair

Lane County, Oregon · 030 MI E HWY101-WOAHINK · Structure no. 39C565532400001

Built
1984
41 years old
Condition
Fair
inspected August 2023
Type
Slab
Prestressed Concrete
Length
24 ft
1 main span
Daily traffic
164
2020 count
Owner
County
County Highway Agency

About this bridge

South Slough Road over South Slough is a prestressed concrete slab carrying South Slough Road over South Slough in Lane County, Oregon. It was built in 1984, so it is 41 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 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 164 vehicles a day, roughly 3% of them trucks, projected to reach 189 by 2025. The structure is 24 ft (7.3 m) long and 28 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

CarriesSouth Slough Road
CrossesSouth Slough
Location030 MI E HWY101-WOAHINK
RouteCounty Highway C5324
StateOregon
Coordinates43.93971, -124.06002
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.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating93 US tons
Inventory rating44 US tons

Structure

Structure typeSlab
MaterialPrestressed Concrete
DeckOther
Main spans1
Design loadHS 20
Structure length24 ft (7.3 m)
Longest span23 ft (7 m)
Deck width28 ft (8.5 m)
Roadway width28 ft (8.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic164 (2020)
Projected traffic189 by 2025
Trucks3%
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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was South Slough Road over South Slough built?

It was built in 1984, making it 41 years old in 2025.

What condition is South Slough Road over South Slough 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 August 2023.

How much traffic does South Slough Road over South Slough carry?

About 164 vehicles per day (2020 count), of which roughly 3% are trucks.

How long is South Slough Road over South Slough?

The structure is 24 ft (7.3 m) long with a longest span of 23 ft (7 m) and a deck 28 ft wide.

Who owns South Slough Road over South Slough?

It is owned by the County Highway Agency.