US Bridges

Fire Road over Siuslaw River

Fair

Lane County, Oregon · 020 MI West of Lorane · Structure no. 39C459439300009

Built
1977
48 years old
Condition
Fair
inspected July 2024
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
101 ft
1 main span
Daily traffic
100
2020 count
Owner
County
County Highway Agency

About this bridge

Fire Road over Siuslaw River is a prestressed concrete box beam or girders - multiple carrying Fire Road over Siuslaw River in Lane County, Oregon. It was built in 1977, so it is 48 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 100 vehicles a day, projected to reach 115 by 2025. The structure is 101 ft (30.8 m) long and 28 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesFire Road
CrossesSiuslaw River
Location020 MI West of Lorane
RouteCounty Highway C4393
CountyLane County
StateOregon
Coordinates43.8258, -123.26868
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 inspectionJuly 2024
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 geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating34.6 US tons
Inventory rating26.8 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete
DeckOther
Main spans1 (+1 approach)
Design loadHS 20
Structure length101 ft (30.8 m)
Longest span72 ft (21.9 m)
Deck width28 ft (8.5 m)
Roadway width28 ft (8.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic100 (2020)
Projected traffic115 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 statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Fire Road over Siuslaw River built?

It was built in 1977, making it 48 years old in 2025.

What condition is Fire Road over Siuslaw 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 July 2024.

How much traffic does Fire Road over Siuslaw River carry?

About 100 vehicles per day (2020 count).

How long is Fire Road over Siuslaw River?

The structure is 101 ft (30.8 m) long with a longest span of 72 ft (21.9 m) and a deck 28 ft wide.

Who owns Fire Road over Siuslaw River?

It is owned by the County Highway Agency.