US Bridges

68th Ave NE over Sammamish River

Fair

King County, Washington · 0.5 MI S of SR 522 · Structure no. 081333000000000

Built
1970
55 years old
Condition
Fair
inspected June 2024
Type
Box Beam or Girders - Single or Spread
Prestressed Concrete Continuous
Length
590 ft
5 main spans
Daily traffic
24,000
2020 count
Owner
City
City or Municipal Highway Agency

About this bridge

68th Ave NE over Sammamish River is a prestressed concrete continuous box beam or girders - single or spread carrying 68th Ave NE over Sammamish River in King County, Washington. It was built in 1970, so it is 55 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 24,000 vehicles a day, roughly 5% of them trucks, projected to reach 38,000 by 2042. The structure is 590 ft (179.8 m) long and 36 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

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Carries68th Ave NE
CrossesSammamish River
Location0.5 MI S of SR 522
RouteCounty Highway 609
CountyKing County
StateWashington
Coordinates47.75401, -122.24978
Functional classUrban Other Principal 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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJune 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating46.1 US tons
Inventory rating19 US tons

Structure

Structure typeBox Beam or Girders - Single or Spread
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans5
Design loadHS 20
Structure length590 ft (179.8 m)
Longest span140 ft (42.7 m)
Deck width36 ft (11 m)
Roadway width28 ft (8.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic24,000 (2020)
Projected traffic38,000 by 2042
Trucks5%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed5 mi (8 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal 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$21.7 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was 68th Ave NE over Sammamish River built?

It was built in 1970, making it 55 years old in 2025.

What condition is 68th Ave NE over Sammamish 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 June 2024.

How much traffic does 68th Ave NE over Sammamish River carry?

About 24,000 vehicles per day (2020 count), of which roughly 5% are trucks.

How long is 68th Ave NE over Sammamish River?

The structure is 590 ft (179.8 m) long with a longest span of 140 ft (42.7 m) and a deck 36 ft wide.

Who owns 68th Ave NE over Sammamish River?

It is owned by the City or Municipal Highway Agency.