US Bridges

188 SW over Overflow Channel

Fair

Thurston County, Washington · 700 Ft W Marble ST SW · Structure no. 080506000000000

Built
1981
44 years old
Condition
Fair
inspected June 2023
Type
Culvert
Steel
Length
30 ft
3 main spans
Daily traffic
291
2021 count
Owner
County
County Highway Agency

About this bridge

188 SW over Overflow Channel is a steel culvert carrying 188 SW over Overflow Channel in Thurston County, Washington. It was built in 1981, so it is 44 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 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 291 vehicles a day, roughly 10% of them trucks, projected to reach 450 by 2043. The structure is 30 ft (9.1 m) long. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
Carries188 SW
CrossesOverflow Channel
Location700 Ft W Marble ST SW
RouteCounty Highway 16155
CountyThurston County
StateWashington
Coordinates46.81454, -123.10354
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
Channel and channel protection7 GoodSome minor problems.
Culvert5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating55 US tons
Inventory rating42 US tons

Structure

Structure typeCulvert
MaterialSteel
DeckNot applicable
Main spans3
Design loadHL 93
Structure length30 ft (9.1 m)
Longest span8 ft (2.4 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic291 (2021)
Projected traffic450 by 2043
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 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 proposedWidening of existing bridge without deck rehabilitation
Estimated improvement cost$328,000 (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was 188 SW over Overflow Channel built?

It was built in 1981, making it 44 years old in 2025.

What condition is 188 SW over Overflow Channel 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 188 SW over Overflow Channel carry?

About 291 vehicles per day (2021 count), of which roughly 10% are trucks.

How long is 188 SW over Overflow Channel?

The structure is 30 ft (9.1 m) long with a longest span of 8 ft (2.4 m).

Who owns 188 SW over Overflow Channel?

It is owned by the County Highway Agency.