US Bridges

S Fragger Road over Mullen Slough

FairPosted for load

King County, Washington · 0.4 MI S JCT SR-516 · Structure no. 085399000000000

Built
1950
75 years old
Condition
Fair
inspected April 2024
Type
Slab
Concrete Continuous
Length
66 ft
3 main spans
Daily traffic
1,600
2020 count
Owner
City
City or Municipal Highway Agency

About this bridge

S Fragger Road over Mullen Slough is a concrete continuous slab carrying S Fragger Road over Mullen Slough in King County, Washington. It was built in 1950, so it is 75 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. Its operating status is: posted for load restriction.

It carries about 1,600 vehicles a day, roughly 1% of them trucks, projected to reach 1,950 by 2040. The structure is 66 ft (20.1 m) long and 29 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

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CarriesS Fragger Road
CrossesMullen Slough
Location0.4 MI S JCT SR-516
RouteCity Street 615
CountyKing County
StateWashington
Coordinates47.37619, -122.26575
Functional classUrban Local

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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating21.4 US tons
Inventory rating16.4 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadH 15
Structure length66 ft (20.1 m)
Longest span25 ft (7.6 m)
Deck width29 ft (8.8 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,600 (2020)
Projected traffic1,950 by 2040
Trucks1%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$2.7 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was S Fragger Road over Mullen Slough built?

It was built in 1950, making it 75 years old in 2025.

What condition is S Fragger Road over Mullen Slough 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 April 2024.

How much traffic does S Fragger Road over Mullen Slough carry?

About 1,600 vehicles per day (2020 count), of which roughly 1% are trucks.

How long is S Fragger Road over Mullen Slough?

The structure is 66 ft (20.1 m) long with a longest span of 25 ft (7.6 m) and a deck 29 ft wide.

Who owns S Fragger Road over Mullen Slough?

It is owned by the City or Municipal Highway Agency.