US Bridges

Boistfort Rd. over S.Fork Chehalis River

Fair

Lewis County, Washington · 1.08 S SR 6 · Structure no. 083355000000000

Built
1958
67 years old
Condition
Fair
inspected December 2022
Type
Tee Beam
Concrete Continuous
Length
204 ft
3 main spans
Daily traffic
686
2022 count
Owner
County
County Highway Agency

About this bridge

Boistfort Rd. over S.Fork Chehalis River is a concrete continuous tee beam carrying Boistfort Rd. over S.Fork Chehalis River in Lewis County, Washington. It was built in 1958, so it is 67 years old, older 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 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 686 vehicles a day, roughly 29% of them trucks, projected to reach 1,239 by 2042. The structure is 204 ft (62.2 m) long and 26 ft wide. If it were closed, the detour would be 6.8 mi (11 km).

Location

Open in Google Maps
CarriesBoistfort Rd.
CrossesS.Fork Chehalis River
Location1.08 S SR 6
RouteCounty Highway 92006
CountyLewis County
StateWashington
Coordinates46.58744, -123.1185
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionDecember 2022
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being 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 alignment6: Equal to present minimum criteria
Operating rating34.9 US tons
Inventory rating20.9 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 15
Structure length204 ft (62.2 m)
Longest span84 ft (25.6 m)
Deck width26 ft (8 m)
Roadway width24 ft (7.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic686 (2022)
Projected traffic1,239 by 2042
Trucks29%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.8 mi (11 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 proposedOther structural work, including hydraulic replacements
Estimated improvement cost$2.9 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 1958, making it 67 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 686 vehicles per day (2022 count), of which roughly 29% are trucks.

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

The structure is 204 ft (62.2 m) long with a longest span of 84 ft (25.6 m) and a deck 26 ft wide.

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

It is owned by the County Highway Agency.