US Bridges

SR 304 over Sinclair Inlet

Fair

Kitsap County, Washington · 0.4 E JCT SR 303 · Structure no. 0006825A0000000

Built
1961
64 years old, rebuilt 1997
Condition
Fair
inspected May 2023
Type
Movable - Lift
Steel
Length
105 ft
1 main span
Daily traffic
560
2010 count
Owner
State
State Highway Agency

About this bridge

SR 304 over Sinclair Inlet is a steel movable - lift carrying SR 304 over Sinclair Inlet in Kitsap County, Washington. It was built in 1961 and reconstructed in 1997, so it is 64 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 560 vehicles a day, projected to reach 953 by 2037. The structure is 105 ft (32 m) long and 21 ft wide.

Location

Open in Google Maps
CarriesSR 304
CrossesSinclair Inlet
Location0.4 E JCT SR 303
RouteState Highway 304
CountyKitsap County
StateWashington
Coordinates47.56215, -122.62482
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
Deck7 GoodSome minor problems.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
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 rating40 US tons
Inventory rating24 US tons

Structure

Structure typeMovable - Lift
MaterialSteel
DeckWood or timber
Main spans1
Design loadHS 20 + Mod
Structure length105 ft (32 m)
Longest span90 ft (27.4 m)
Deck width21 ft (6.5 m)
Roadway width19 ft (5.9 m)
Vertical clearance over deck16 ft (4.9 m)

Traffic and service

Average daily traffic560 (2010)
Projected traffic953 by 2037
Trucks0%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed—
TollToll bridge
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$1.2 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SR 304 over Sinclair Inlet built?

It was built in 1961, making it 64 years old in 2025. It was reconstructed in 1997.

What condition is SR 304 over Sinclair Inlet 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 May 2023.

How much traffic does SR 304 over Sinclair Inlet carry?

About 560 vehicles per day (2010 count).

How long is SR 304 over Sinclair Inlet?

The structure is 105 ft (32 m) long with a longest span of 90 ft (27.4 m) and a deck 21 ft wide.

Who owns SR 304 over Sinclair Inlet?

It is owned by the State Highway Agency.