US Bridges

N-N Ramp over SR 515

Good

King County, Washington · JCT SR 515 · Structure no. 0018811A0000000

Built
2017
8 years old
Condition
Good
inspected May 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
176 ft
1 main span
Daily traffic
27,969
2019 count
Owner
State
State Highway Agency

About this bridge

N-N Ramp over SR 515 is a prestressed concrete stringer/multi-beam or girder carrying N-N Ramp over SR 515 in King County, Washington. It was built in 2017, so it is 8 years old, younger 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 8 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 27,969 vehicles a day, roughly 6% of them trucks, projected to reach 66,729 by 2039. The structure is 176 ft (53.6 m) long and 30 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesN-N Ramp
CrossesSR 515
LocationJCT SR 515
RouteInterstate 167
CountyKing County
StateWashington
Coordinates47.46873, -122.20829
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
Deck8 Very GoodNo problems noted.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Last inspectionMay 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation8: Equal to present desirable criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Approach roadway alignment8: Equal to present desirable criteria
Operating rating59 US tons
Inventory rating43.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHL 93
Structure length176 ft (53.6 m)
Longest span170 ft (51.7 m)
Deck width30 ft (9.1 m)
Roadway width27 ft (8.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic27,969 (2019)
Projected traffic66,729 by 2039
Trucks6%
Lanes on structure1
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$4.6 million (2022 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was N-N Ramp over SR 515 built?

It was built in 2017, making it 8 years old in 2025.

What condition is N-N Ramp over SR 515 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 2024.

How much traffic does N-N Ramp over SR 515 carry?

About 27,969 vehicles per day (2019 count), of which roughly 6% are trucks.

How long is N-N Ramp over SR 515?

The structure is 176 ft (53.6 m) long with a longest span of 170 ft (51.7 m) and a deck 30 ft wide.

Who owns N-N Ramp over SR 515?

It is owned by the State Highway Agency.