US Bridges

S-S Ramp over 1st Ave S

Fair

King County, Washington · 4.0 N JCT SR 518 · Structure no. 0008276H0000000

Built
1968
57 years old
Condition
Fair
inspected July 2023
Type
Slab
Concrete Continuous
Length
152 ft
3 main spans
Daily traffic
8,511
2022 count
Owner
State
State Highway Agency

About this bridge

S-S Ramp over 1st Ave S is a concrete continuous slab carrying S-S Ramp over 1st Ave S in King County, Washington. It was built in 1968, so it is 57 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 8,511 vehicles a day, roughly 5% of them trucks, projected to reach 13,987 by 2039. The structure is 152 ft (46.3 m) long and 37 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesS-S Ramp
Crosses1st Ave S
Location4.0 N JCT SR 518
RouteState Highway 509
CountyKing County
StateWashington
Coordinates47.52666, -122.3348
Functional classUrban Principal Arterial - Other Freeway or Expressway

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.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating41.4 US tons
Inventory rating31.7 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length152 ft (46.3 m)
Longest span61 ft (18.6 m)
Deck width37 ft (11.3 m)
Roadway width33 ft (10.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic8,511 (2022)
Projected traffic13,987 by 2039
Trucks5%
Lanes on structure1
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed1.2 mi (2 km)
TollOn a free road
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$2.7 million (2022 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was S-S Ramp over 1st Ave S built?

It was built in 1968, making it 57 years old in 2025.

What condition is S-S Ramp over 1st Ave S 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 July 2023.

How much traffic does S-S Ramp over 1st Ave S carry?

About 8,511 vehicles per day (2022 count), of which roughly 5% are trucks.

How long is S-S Ramp over 1st Ave S?

The structure is 152 ft (46.3 m) long with a longest span of 61 ft (18.6 m) and a deck 37 ft wide.

Who owns S-S Ramp over 1st Ave S?

It is owned by the State Highway Agency.