US Bridges

SR 99 over N 38th ST

Fair

King County, Washington · 8.3 N JCT SR 509 · Structure no. 0001589A0000000

Built
1932
93 years old
Condition
Fair
inspected March 2024
Type
Tee Beam
Concrete Continuous
Length
93 ft
3 main spans
Daily traffic
61,259
2023 count
Owner
State
State Highway Agency

About this bridge

SR 99 over N 38th ST is a concrete continuous tee beam carrying SR 99 over N 38th ST in King County, Washington. It was built in 1932, so it is 93 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 61,259 vehicles a day, roughly 4% of them trucks, projected to reach 100,765 by 2039. The structure is 93 ft (28.3 m) long and 70 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesSR 99
CrossesN 38th ST
Location8.3 N JCT SR 509
RouteState Highway 99
CountyKing County
StateWashington
Coordinates47.65251, -122.34735
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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMarch 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Approach roadway alignment8: Equal to present desirable criteria
Operating rating26.5 US tons
Inventory rating20.4 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadUnknown
Structure length93 ft (28.3 m)
Longest span52 ft (15.8 m)
Deck width70 ft (21.2 m)
Roadway width57 ft (17.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic61,259 (2023)
Projected traffic100,765 by 2039
Trucks4%
Lanes on structure5
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
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$2.6 million (2022 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was SR 99 over N 38th ST built?

It was built in 1932, making it 93 years old in 2025.

What condition is SR 99 over N 38th ST 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 March 2024.

How much traffic does SR 99 over N 38th ST carry?

About 61,259 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is SR 99 over N 38th ST?

The structure is 93 ft (28.3 m) long with a longest span of 52 ft (15.8 m) and a deck 70 ft wide.

Who owns SR 99 over N 38th ST?

It is owned by the State Highway Agency.