US Bridges

SR 525 over Possession Sound

Fair

Island County, Washington · 1.9 N JCT SR 526 · Structure no. 0004101A0000000

Built
1987
38 years old, rebuilt 2000
Condition
Fair
inspected June 2023
Type
Movable - Lift
Steel
Length
105 ft
1 main span
Daily traffic
12,000
2010 count
Owner
State
State Highway Agency

About this bridge

SR 525 over Possession Sound is a steel movable - lift carrying SR 525 over Possession Sound in Island County, Washington. It was built in 1987 and reconstructed in 2000, so it is 38 years old, younger 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 12,000 vehicles a day, roughly 5% of them trucks, projected to reach 21,048 by 2036. The structure is 105 ft (32 m) long and 24 ft wide.

Location

Open in Google Maps
CarriesSR 525
CrossesPossession Sound
Location1.9 N JCT SR 526
RouteState Highway 525
CountyIsland County
StateWashington
Coordinates47.975, -122.34833
Functional classRural Principal Arterial - Other

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.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJune 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 rating42 US tons
Inventory rating25 US tons

Structure

Structure typeMovable - Lift
MaterialSteel
DeckClosed grating
Main spans1
Design loadHS 20
Structure length105 ft (32 m)
Longest span80 ft (24.4 m)
Deck width24 ft (7.3 m)
Roadway width20 ft (6.1 m)
Vertical clearance over deck16 ft (4.9 m)

Traffic and service

Average daily traffic12,000 (2010)
Projected traffic21,048 by 2036
Trucks5%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed—
TollToll bridge
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
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 525 over Possession Sound built?

It was built in 1987, making it 38 years old in 2025. It was reconstructed in 2000.

What condition is SR 525 over Possession Sound 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 2023.

How much traffic does SR 525 over Possession Sound carry?

About 12,000 vehicles per day (2010 count), of which roughly 5% are trucks.

How long is SR 525 over Possession Sound?

The structure is 105 ft (32 m) long with a longest span of 80 ft (24.4 m) and a deck 24 ft wide.

Who owns SR 525 over Possession Sound?

It is owned by the State Highway Agency.