US Bridges

SR 20 over State Park Road/Trail

Good

Island County, Washington · 25.2 E JCT SR 525 · Structure no. 000000JG0000000

Built
1935
90 years old
Condition
Good
inspected May 2024
Type
Slab
Concrete
Length
21 ft
1 main span
Daily traffic
18,797
2023 count
Owner
State
State Highway Agency

About this bridge

SR 20 over State Park Road/Trail is a concrete slab carrying SR 20 over State Park Road/Trail in Island County, Washington. It was built in 1935, so it is 90 years old, older than the Washington average of 49.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 18,797 vehicles a day, roughly 6% of them trucks, projected to reach 26,979 by 2039. The structure is 21 ft (6.4 m) long and 30 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

Location

Open in Google Maps
CarriesSR 20
CrossesState Park Road/Trail
Location25.2 E JCT SR 525
RouteState Highway 20
CountyIsland County
StateWashington
Coordinates48.40197, -122.64464
Functional classRural Principal Arterial - Other

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Last inspectionMay 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Approach roadway alignment8: Equal to present desirable criteria
Operating rating45 US tons
Inventory rating27 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadUnknown
Structure length21 ft (6.4 m)
Longest span21 ft (6.4 m)
Deck width30 ft (9 m)
Roadway width26 ft (8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic18,797 (2023)
Projected traffic26,979 by 2039
Trucks6%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesPedestrian / bicycle
Detour if closed98.8 mi (159 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkSTRAHNET connector

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusListed on the National Register of Historic Places
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$289,000 (2022 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was SR 20 over State Park Road/Trail built?

It was built in 1935, making it 90 years old in 2025.

What condition is SR 20 over State Park Road/Trail in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in May 2024.

How much traffic does SR 20 over State Park Road/Trail carry?

About 18,797 vehicles per day (2023 count), of which roughly 6% are trucks.

How long is SR 20 over State Park Road/Trail?

The structure is 21 ft (6.4 m) long with a longest span of 21 ft (6.4 m) and a deck 30 ft wide.

Who owns SR 20 over State Park Road/Trail?

It is owned by the State Highway Agency.