US Bridges

Porter Creek Road over Overflow Channel

Good

Grays Harbor County, Washington · 0.5 W JCT SR 12 · Structure no. 088225000000000

Built
2010
15 years old
Condition
Good
inspected October 2024
Type
Slab
Prestressed Concrete
Length
226 ft
4 main spans
Daily traffic
821
2020 count
Owner
County
County Highway Agency

About this bridge

Porter Creek Road over Overflow Channel is a prestressed concrete slab carrying Porter Creek Road over Overflow Channel in Grays Harbor County, Washington. It was built in 2010, so it is 15 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 821 vehicles a day, roughly 20% of them trucks, projected to reach 1,001 by 2044. The structure is 226 ft (68.9 m) long and 36 ft wide. If it were closed, the detour would be 19.3 mi (31 km).

CarriesPorter Creek Road
CrossesOverflow Channel
Location0.5 W JCT SR 12
RouteCounty Highway 96540
Coordinates46.93931, -123.32167
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.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating69.7 US tons
Inventory rating41.8 US tons

Structure

Structure typeSlab
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans4
Design loadHL 93
Structure length226 ft (68.9 m)
Longest span55 ft (16.9 m)
Deck width36 ft (11 m)
Roadway width32 ft (9.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic821 (2020)
Projected traffic1,001 by 2044
Trucks20%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesRelief for waterway
Detour if closed19.3 mi (31 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 proposedDeck rehabilitation with only incidental widening
Estimated improvement cost$3.7 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Porter Creek Road over Overflow Channel built?

It was built in 2010, making it 15 years old in 2025.

What condition is Porter Creek Road over Overflow Channel 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 October 2024.

How much traffic does Porter Creek Road over Overflow Channel carry?

About 821 vehicles per day (2020 count), of which roughly 20% are trucks.

How long is Porter Creek Road over Overflow Channel?

The structure is 226 ft (68.9 m) long with a longest span of 55 ft (16.9 m) and a deck 36 ft wide.

Who owns Porter Creek Road over Overflow Channel?

It is owned by the County Highway Agency.