US Bridges

South Bank Road over Chehalis River Overflow

Good

Grays Harbor County, Washington · 1.4 SW JCT SR 12 · Structure no. 088571000000000

Built
2013
12 years old
Condition
Good
inspected January 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete Continuous
Length
253 ft
3 main spans
Daily traffic
1,110
2020 count
Owner
County
County Highway Agency

About this bridge

South Bank Road over Chehalis River Overflow is a prestressed concrete continuous stringer/multi-beam or girder carrying South Bank Road over Chehalis River Overflow in Grays Harbor County, Washington. It was built in 2013, so it is 12 years old, younger than the Washington average of 49.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 1,110 vehicles a day, roughly 22% of them trucks, projected to reach 1,332 by 2040. The structure is 253 ft (77.1 m) long and 35 ft wide. If it were closed, the detour would be 18 mi (29 km).

CarriesSouth Bank Road
CrossesChehalis River Overflow
Location1.4 SW JCT SR 12
RouteCounty Highway 96411
Coordinates46.83, -123.25
Functional classRural Major Collector

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure8 Very GoodNo problems noted.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJanuary 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than 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 rating55.3 US tons
Inventory rating38.3 US tons

Structure

MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHL 93
Structure length253 ft (77.1 m)
Longest span83 ft (25.4 m)
Deck width35 ft (10.7 m)
Roadway width32 ft (9.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,110 (2020)
Projected traffic1,332 by 2040
Trucks22%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesRelief for waterway
Detour if closed18 mi (29 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$9.5 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was South Bank Road over Chehalis River Overflow built?

It was built in 2013, making it 12 years old in 2025.

What condition is South Bank Road over Chehalis River Overflow in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in January 2024.

How much traffic does South Bank Road over Chehalis River Overflow carry?

About 1,110 vehicles per day (2020 count), of which roughly 22% are trucks.

How long is South Bank Road over Chehalis River Overflow?

The structure is 253 ft (77.1 m) long with a longest span of 83 ft (25.4 m) and a deck 35 ft wide.

Who owns South Bank Road over Chehalis River Overflow?

It is owned by the County Highway Agency.