US Bridges

I-90 over Naneum CR

Good

Kittitas County, Washington · 1.2 E JCT I-82 · Structure no. 002000550000000

Built
1970
55 years old
Condition
Good
inspected February 2022
Type
Culvert
Steel
Length
25 ft
2 main spans
Daily traffic
9,167
2023 count
Owner
State
State Highway Agency

About this bridge

I-90 over Naneum CR is a steel culvert carrying I-90 over Naneum CR in Kittitas County, Washington. It was built in 1970, so it is 55 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 9,167 vehicles a day, roughly 28% of them trucks, projected to reach 11,046 by 2039. The structure is 25 ft (7.6 m) long. If it were closed, the detour would be 3.1 mi (5 km).

Location

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CarriesI-90
CrossesNaneum CR
Location1.2 E JCT I-82
RouteInterstate 90
CountyKittitas County
StateWashington
Coordinates46.97056, -120.48417
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
Channel and channel protection8 Very GoodNo problems noted.
Culvert7 GoodSome minor problems.
Last inspectionFebruary 2022
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating99 US tons
Inventory rating99 US tons

Structure

Structure typeCulvert
MaterialSteel
DeckNot applicable
Main spans2
Design loadUnknown
Structure length25 ft (7.6 m)
Longest span11 ft (3.4 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic9,167 (2023)
Projected traffic11,046 by 2039
Trucks28%
Lanes on structure4
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 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$451,000 (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was I-90 over Naneum CR built?

It was built in 1970, making it 55 years old in 2025.

What condition is I-90 over Naneum CR 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 February 2022.

How much traffic does I-90 over Naneum CR carry?

About 9,167 vehicles per day (2023 count), of which roughly 28% are trucks.

How long is I-90 over Naneum CR?

The structure is 25 ft (7.6 m) long with a longest span of 11 ft (3.4 m).

Who owns I-90 over Naneum CR?

It is owned by the State Highway Agency.