US Bridges

Boistfort Rd. over S.Fork Chehalis River

Fair

Lewis County, Washington · 8.0 SW Chehalis · Structure no. 079741000000000

Built
1982
43 years old
Condition
Fair
inspected December 2022
Type
Stringer/Multi-beam or Girder
Prestressed Concrete Continuous
Length
440 ft
3 main spans
Daily traffic
847
2022 count
Owner
County
County Highway Agency

About this bridge

Boistfort Rd. over S.Fork Chehalis River is a prestressed concrete continuous stringer/multi-beam or girder carrying Boistfort Rd. over S.Fork Chehalis River in Lewis County, Washington. It was built in 1982, so it is 43 years old, younger than the Washington average of 49.8 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 847 vehicles a day, roughly 21% of them trucks, projected to reach 1,529 by 2042. The structure is 440 ft (134.1 m) long and 35 ft wide. If it were closed, the detour would be 29.2 mi (47 km).

Location

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CarriesBoistfort Rd.
CrossesS.Fork Chehalis River
Location8.0 SW Chehalis
RouteCounty Highway 92006
CountyLewis County
StateWashington
Coordinates46.54725, -123.13296
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionDecember 2022
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourCountermeasures installed to correct a previously existing problem
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 alignment8: Equal to present desirable criteria
Operating rating71 US tons
Inventory rating42 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans3 (+9 approach)
Design loadHS 20
Structure length440 ft (134.1 m)
Longest span74 ft (22.6 m)
Deck width35 ft (10.7 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic847 (2022)
Projected traffic1,529 by 2042
Trucks21%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed29.2 mi (47 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 proposedOther structural work, including hydraulic replacements
Estimated improvement cost$9.4 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Boistfort Rd. over S.Fork Chehalis River built?

It was built in 1982, making it 43 years old in 2025.

What condition is Boistfort Rd. over S.Fork Chehalis 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 December 2022.

How much traffic does Boistfort Rd. over S.Fork Chehalis River carry?

About 847 vehicles per day (2022 count), of which roughly 21% are trucks.

How long is Boistfort Rd. over S.Fork Chehalis River?

The structure is 440 ft (134.1 m) long with a longest span of 74 ft (22.6 m) and a deck 35 ft wide.

Who owns Boistfort Rd. over S.Fork Chehalis River?

It is owned by the County Highway Agency.