US Bridges

148th Ave SE over Soos Creek

Fair

King County, Washington · 2.5 MI N of SR-516 · Structure no. 081672000000000

Built
1971
54 years old
Condition
Fair
inspected July 2023
Type
Channel Beam
Prestressed Concrete
Length
32 ft
1 main span
Daily traffic
4,306
2023 count
Owner
County
County Highway Agency

About this bridge

148th Ave SE over Soos Creek is a prestressed concrete channel beam carrying 148th Ave SE over Soos Creek in King County, Washington. It was built in 1971, so it is 54 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 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 4,306 vehicles a day, roughly 4% of them trucks, projected to reach 6,050 by 2043. The structure is 32 ft (9.8 m) long and 38 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
Carries148th Ave SE
CrossesSoos Creek
Location2.5 MI N of SR-516
RouteCounty Highway 18500
CountyKing County
StateWashington
Coordinates47.38643, -122.14407
Functional classUrban Collector

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.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourUnknown foundation; not evaluated for scour
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
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating36 US tons
Inventory rating28 US tons

Structure

Structure typeChannel Beam
MaterialPrestressed Concrete
DeckOther
Main spans1
Design loadHS 20
Structure length32 ft (9.8 m)
Longest span23 ft (7 m)
Deck width38 ft (11.6 m)
Roadway width31 ft (9.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,306 (2023)
Projected traffic6,050 by 2043
Trucks4%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed3.7 mi (6 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$1 million
NavigationNo navigation control on waterway

Frequently asked questions

When was 148th Ave SE over Soos Creek built?

It was built in 1971, making it 54 years old in 2025.

What condition is 148th Ave SE over Soos Creek 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 148th Ave SE over Soos Creek carry?

About 4,306 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is 148th Ave SE over Soos Creek?

The structure is 32 ft (9.8 m) long with a longest span of 23 ft (7 m) and a deck 38 ft wide.

Who owns 148th Ave SE over Soos Creek?

It is owned by the County Highway Agency.