US Bridges

Cedar Grove RD over Issaquah Creek

Fair

King County, Washington · 2 MI E of SR-169 · Structure no. 083002000000000

Built
1962
63 years old
Condition
Fair
inspected September 2024
Type
Slab
Prestressed Concrete
Length
42 ft
1 main span
Daily traffic
4,568
2020 count
Owner
County
County Highway Agency

About this bridge

Cedar Grove RD over Issaquah Creek is a prestressed concrete slab carrying Cedar Grove RD over Issaquah Creek 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 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 4,568 vehicles a day, roughly 10% of them trucks, projected to reach 8,250 by 2040. The structure is 42 ft (12.8 m) long and 30 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesCedar Grove RD
CrossesIssaquah Creek
Location2 MI E of SR-169
RouteCounty Highway 98579
CountyKing County
StateWashington
Coordinates47.46244, -122.0255
Functional classUrban Minor Arterial

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.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionSeptember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating60 US tons
Inventory rating36 US tons

Structure

Structure typeSlab
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans1
Design loadHS 20
Structure length42 ft (12.8 m)
Longest span40 ft (12.2 m)
Deck width30 ft (9.1 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,568 (2020)
Projected traffic8,250 by 2040
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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$1.9 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Cedar Grove RD over Issaquah Creek built?

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

What condition is Cedar Grove RD over Issaquah Creek 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 September 2024.

How much traffic does Cedar Grove RD over Issaquah Creek carry?

About 4,568 vehicles per day (2020 count), of which roughly 10% are trucks.

How long is Cedar Grove RD over Issaquah Creek?

The structure is 42 ft (12.8 m) long with a longest span of 40 ft (12.2 m) and a deck 30 ft wide.

Who owns Cedar Grove RD over Issaquah Creek?

It is owned by the County Highway Agency.