US Bridges

I-90 over Rocky Run Creek

Good

Kittitas County, Washington · 2.1 E JCT SR 906 · Structure no. 0017852F0000000

Built
2012
13 years old
Condition
Good
inspected October 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
120 ft
1 main span
Daily traffic
18,069
2023 count
Owner
State
State Highway Agency

About this bridge

I-90 over Rocky Run Creek is a prestressed concrete stringer/multi-beam or girder carrying I-90 over Rocky Run Creek in Kittitas County, Washington. It was built in 2012, so it is 13 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 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 18,069 vehicles a day, roughly 21% of them trucks, projected to reach 22,265 by 2039. The structure is 120 ft (36.6 m) long and 78 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesI-90
CrossesRocky Run Creek
Location2.1 E JCT SR 906
RouteInterstate 90
CountyKittitas County
StateWashington
Coordinates47.37284, -121.37624
Functional classRural 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.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation8: Equal to present desirable criteria
Deck geometry9: Superior to present desirable criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating63.2 US tons
Inventory rating47.2 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHL 93
Structure length120 ft (36.6 m)
Longest span115 ft (35.1 m)
Deck width78 ft (23.8 m)
Roadway width76 ft (23.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic18,069 (2023)
Projected traffic22,265 by 2039
Trucks21%
Lanes on structure3
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
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 statusHistorical significance not determinable at this time
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$4.4 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was I-90 over Rocky Run Creek built?

It was built in 2012, making it 13 years old in 2025.

What condition is I-90 over Rocky Run Creek 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 October 2023.

How much traffic does I-90 over Rocky Run Creek carry?

About 18,069 vehicles per day (2023 count), of which roughly 21% are trucks.

How long is I-90 over Rocky Run Creek?

The structure is 120 ft (36.6 m) long with a longest span of 115 ft (35.1 m) and a deck 78 ft wide.

Who owns I-90 over Rocky Run Creek?

It is owned by the State Highway Agency.