US Bridges

West Lake Road over Siltcoos River

Fair

Lane County, Oregon · 0047 MI E HWY101-WESTLAKE · Structure no. 39C577535000047

Built
1975
50 years old
Condition
Fair
inspected August 2023
Type
Channel Beam
Prestressed Concrete
Length
193 ft
3 main spans
Daily traffic
984
2020 count
Owner
County
County Highway Agency

About this bridge

West Lake Road over Siltcoos River is a prestressed concrete channel beam carrying West Lake Road over Siltcoos River in Lane County, Oregon. It was built in 1975, so it is 50 years old, older 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 984 vehicles a day, roughly 10% of them trucks, projected to reach 1,124 by 2025. The structure is 193 ft (58.8 m) long and 29 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesWest Lake Road
CrossesSiltcoos River
Location0047 MI E HWY101-WESTLAKE
RouteCounty Highway C5350
CountyLane County
StateOregon
Coordinates43.88189, -124.11424
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
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating32.5 US tons
Inventory rating25 US tons

Structure

Structure typeChannel Beam
MaterialPrestressed Concrete
DeckOther
Main spans3
Design loadHS 20
Structure length193 ft (58.8 m)
Longest span64 ft (19.5 m)
Deck width29 ft (8.7 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic984 (2020)
Projected traffic1,124 by 2025
Trucks10%
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 statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was West Lake Road over Siltcoos River built?

It was built in 1975, making it 50 years old in 2025.

What condition is West Lake Road over Siltcoos River 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 West Lake Road over Siltcoos River carry?

About 984 vehicles per day (2020 count), of which roughly 10% are trucks.

How long is West Lake Road over Siltcoos River?

The structure is 193 ft (58.8 m) long with a longest span of 64 ft (19.5 m) and a deck 29 ft wide.

Who owns West Lake Road over Siltcoos River?

It is owned by the County Highway Agency.