US Bridges

SR 509 over 1st Ave S

Good

King County, Washington · 5.0 N Pierce CO · Structure no. 0006621A0000000

Built
1961
64 years old
Condition
Good
inspected August 2023
Type
Slab
Concrete Continuous
Length
83 ft
3 main spans
Daily traffic
12,319
2023 count
Owner
State
State Highway Agency

About this bridge

SR 509 over 1st Ave S is a concrete continuous slab carrying SR 509 over 1st Ave S in King County, Washington. It was built in 1961, 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 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 12,319 vehicles a day, roughly 3% of them trucks, projected to reach 17,648 by 2039. The structure is 83 ft (25.3 m) long and 36 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesSR 509
Crosses1st Ave S
Location5.0 N Pierce CO
RouteState Highway 509
CountyKing County
StateWashington
Coordinates47.33081, -122.33478
Functional classUrban Minor Arterial

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 inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment3: Basically intolerable, requiring high priority of corrective action
Operating rating39 US tons
Inventory rating23 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 15
Structure length83 ft (25.3 m)
Longest span33 ft (10.1 m)
Deck width36 ft (11 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic12,319 (2023)
Projected traffic17,648 by 2039
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemNo

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$1.3 million (2022 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was SR 509 over 1st Ave S built?

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

What condition is SR 509 over 1st Ave S 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 August 2023.

How much traffic does SR 509 over 1st Ave S carry?

About 12,319 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is SR 509 over 1st Ave S?

The structure is 83 ft (25.3 m) long with a longest span of 33 ft (10.1 m) and a deck 36 ft wide.

Who owns SR 509 over 1st Ave S?

It is owned by the State Highway Agency.