US Bridges

Coughlin Road over S Fk Newaukum River

Fair

Lewis County, Washington · 1.0 E Onalaska · Structure no. 084294000000000

Built
1922
103 years old, rebuilt 1966
Condition
Fair
inspected March 2023
Type
Truss - Thru
Steel
Length
100 ft
1 main span
Daily traffic
27
2020 count
Owner
County
County Highway Agency

About this bridge

Coughlin Road over S Fk Newaukum River is a steel truss - thru carrying Coughlin Road over S Fk Newaukum River in Lewis County, Washington. It was built in 1922 and reconstructed in 1966, so it is 103 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 27 vehicles a day, roughly 11% of them trucks, projected to reach 49 by 2040. The structure is 100 ft (30.5 m) long and 18 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

Location

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CarriesCoughlin Road
CrossesS Fk Newaukum River
Location1.0 E Onalaska
RouteCounty Highway 46022
CountyLewis County
StateWashington
Coordinates46.57483, -122.70494
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
Deck8 Very GoodNo problems noted.
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 protection7 GoodSome minor problems.
Last inspectionMarch 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourCountermeasures installed to correct a previously existing problem
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating54 US tons
Inventory rating32 US tons

Structure

Structure typeTruss - Thru
MaterialSteel
DeckWood or timber
Main spans1 (+1 approach)
Design loadH 20
Structure length100 ft (30.5 m)
Longest span81 ft (24.7 m)
Deck width18 ft (5.5 m)
Roadway width17 ft (5.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic27 (2020)
Projected traffic49 by 2040
Trucks11%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed98.8 mi (159 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$4 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Coughlin Road over S Fk Newaukum River built?

It was built in 1922, making it 103 years old in 2025. It was reconstructed in 1966.

What condition is Coughlin Road over S Fk Newaukum 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 March 2023.

How much traffic does Coughlin Road over S Fk Newaukum River carry?

About 27 vehicles per day (2020 count), of which roughly 11% are trucks.

How long is Coughlin Road over S Fk Newaukum River?

The structure is 100 ft (30.5 m) long with a longest span of 81 ft (24.7 m) and a deck 18 ft wide.

Who owns Coughlin Road over S Fk Newaukum River?

It is owned by the County Highway Agency.