US Bridges

I-5 S Ramp to 45th over 50th Ramp to I-5 S

Good

King County, Washington · 1.4 N JCT SR 520 · Structure no. 0006304B0000000

Built
1961
64 years old
Condition
Good
inspected May 2023
Type
Box Beam or Girders - Multiple
Concrete Continuous
Length
243 ft
4 main spans
Daily traffic
10,013
2022 count
Owner
State
State Highway Agency

About this bridge

I-5 S Ramp to 45th over 50th Ramp to I-5 S is a concrete continuous box beam or girders - multiple carrying I-5 S Ramp to 45th over 50th Ramp to I-5 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 10,013 vehicles a day, roughly 5% of them trucks, projected to reach 14,818 by 2039. The structure is 243 ft (74.1 m) long and 27 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

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CarriesI-5 S Ramp to 45th
Crosses50th Ramp to I-5 S
Location1.4 N JCT SR 520
RouteInterstate 5
CountyKing County
StateWashington
Coordinates47.663, -122.3225
Functional classUrban Principal Arterial - Interstate

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 inspectionMay 2023
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating84 US tons
Inventory rating48.9 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length243 ft (74.1 m)
Longest span70 ft (21.3 m)
Deck width27 ft (8.3 m)
Roadway width22 ft (6.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic10,013 (2022)
Projected traffic14,818 by 2039
Trucks5%
Lanes on structure1
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed1.9 mi (3 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$3 million (2022 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was I-5 S Ramp to 45th over 50th Ramp to I-5 S built?

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

What condition is I-5 S Ramp to 45th over 50th Ramp to I-5 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 May 2023.

How much traffic does I-5 S Ramp to 45th over 50th Ramp to I-5 S carry?

About 10,013 vehicles per day (2022 count), of which roughly 5% are trucks.

How long is I-5 S Ramp to 45th over 50th Ramp to I-5 S?

The structure is 243 ft (74.1 m) long with a longest span of 70 ft (21.3 m) and a deck 27 ft wide.

Who owns I-5 S Ramp to 45th over 50th Ramp to I-5 S?

It is owned by the State Highway Agency.