US Bridges

Cedar Flats Road over Swift Creek

Good

Thurston County, Washington · 1.28 M W of Delphi RD · Structure no. 087966000000000

Built
2008
17 years old
Condition
Good
inspected September 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
91 ft
1 main span
Daily traffic
887
2020 count
Owner
County
County Highway Agency

About this bridge

Cedar Flats Road over Swift Creek is a prestressed concrete stringer/multi-beam or girder carrying Cedar Flats Road over Swift Creek in Thurston County, Washington. It was built in 2008, so it is 17 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 887 vehicles a day, roughly 15% of them trucks, projected to reach 1,371 by 2042. The structure is 91 ft (27.7 m) long and 30 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

Location

Open in Google Maps
CarriesCedar Flats Road
CrossesSwift Creek
Location1.28 M W of Delphi RD
RouteCounty Highway 10735
CountyThurston County
StateWashington
Coordinates47.02766, -123.01854
Functional classRural Local

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 inspectionSeptember 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 rating99 US tons
Inventory rating76.9 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHL 93
Structure length91 ft (27.7 m)
Longest span87 ft (26.5 m)
Deck width30 ft (9.1 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic887 (2020)
Projected traffic1,371 by 2042
Trucks15%
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$3.6 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Cedar Flats Road over Swift Creek built?

It was built in 2008, making it 17 years old in 2025.

What condition is Cedar Flats Road over Swift Creek 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 September 2024.

How much traffic does Cedar Flats Road over Swift Creek carry?

About 887 vehicles per day (2020 count), of which roughly 15% are trucks.

How long is Cedar Flats Road over Swift Creek?

The structure is 91 ft (27.7 m) long with a longest span of 87 ft (26.5 m) and a deck 30 ft wide.

Who owns Cedar Flats Road over Swift Creek?

It is owned by the County Highway Agency.