US Bridges

Cedar Grove RD over Cedar River

Fair

King County, Washington · 0.2 MI E of SR-169 · Structure no. 084308000000000

Built
1962
63 years old
Condition
Fair
inspected August 2024
Type
Girder and Floorbeam System
Concrete
Length
189 ft
3 main spans
Daily traffic
5,971
2019 count
Owner
County
County Highway Agency

About this bridge

Cedar Grove RD over Cedar River is a concrete girder and floorbeam system carrying Cedar Grove RD over Cedar River in King County, Washington. It was built in 1962, so it is 63 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 6 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 5,971 vehicles a day, roughly 38% of them trucks, projected to reach 10,785 by 2039. The structure is 189 ft (57.6 m) long and 30 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesCedar Grove RD
CrossesCedar River
Location0.2 MI E of SR-169
RouteCounty Highway 98579
CountyKing County
StateWashington
Coordinates47.43978, -122.06426
Functional classRural Major Collector

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourCountermeasures installed to correct a previously existing problem
Structural evaluation6: Equal to present minimum criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating53.2 US tons
Inventory rating40 US tons

Structure

Structure typeGirder and Floorbeam System
MaterialConcrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length189 ft (57.6 m)
Longest span100 ft (30.5 m)
Deck width30 ft (9.1 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic5,971 (2019)
Projected traffic10,785 by 2039
Trucks38%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 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$7.2 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Cedar Grove RD over Cedar River built?

It was built in 1962, making it 63 years old in 2025.

What condition is Cedar Grove RD over Cedar 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 August 2024.

How much traffic does Cedar Grove RD over Cedar River carry?

About 5,971 vehicles per day (2019 count), of which roughly 38% are trucks.

How long is Cedar Grove RD over Cedar River?

The structure is 189 ft (57.6 m) long with a longest span of 100 ft (30.5 m) and a deck 30 ft wide.

Who owns Cedar Grove RD over Cedar River?

It is owned by the County Highway Agency.