US Bridges

Or 229 (hwy 181) over Siletz River

FairPosted for load

Lincoln County, Oregon · 004 MI N Siletz · Structure no. 00851A181 02310

Built
1956
69 years old
Condition
Fair
inspected June 2023
Type
Truss - Thru
Steel
Length
352 ft
1 main span
Daily traffic
1,109
2022 count
Owner
State
State Highway Agency

About this bridge

Or 229 (hwy 181) over Siletz River is a steel truss - thru carrying Or 229 (hwy 181) over Siletz River in Lincoln County, Oregon. It was built in 1956, so it is 69 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 5 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. Its operating status is: posted for other load-capacity restriction.

It carries about 1,109 vehicles a day, roughly 17% of them trucks, projected to reach 1,300 by 2042. The structure is 352 ft (107.4 m) long and 35 ft wide. If it were closed, the detour would be 32.9 mi (53 km).

Location

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CarriesOr 229 (hwy 181)
CrossesSiletz River
Location004 MI N Siletz
RouteState Highway 229
CountyLincoln County
StateOregon
Coordinates44.73245, -123.91796
Functional classRural Major 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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusPosted for other load-capacity restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating20.4 US tons
Inventory rating15.8 US tons

Structure

Structure typeTruss - Thru
MaterialSteel
DeckConcrete, cast-in-place
Main spans1 (+4 approach)
Design loadHS 15
Structure length352 ft (107.4 m)
Longest span190 ft (58 m)
Deck width35 ft (10.7 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deck15 ft (4.6 m)

Traffic and service

Average daily traffic1,109 (2022)
Projected traffic1,300 by 2042
Trucks17%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed32.9 mi (53 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusPossibly eligible for the National Register; requires further investigation
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$2 million
NavigationNo navigation control on waterway

Frequently asked questions

When was Or 229 (hwy 181) over Siletz River built?

It was built in 1956, making it 69 years old in 2025.

What condition is Or 229 (hwy 181) over Siletz 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 June 2023.

How much traffic does Or 229 (hwy 181) over Siletz River carry?

About 1,109 vehicles per day (2022 count), of which roughly 17% are trucks.

How long is Or 229 (hwy 181) over Siletz River?

The structure is 352 ft (107.4 m) long with a longest span of 190 ft (58 m) and a deck 35 ft wide.

Who owns Or 229 (hwy 181) over Siletz River?

It is owned by the State Highway Agency.