US Bridges

I-90 over Umptanum RD

Good

Kittitas County, Washington · 2.2 E JCT US 97 · Structure no. 0008200D0000000

Built
1967
58 years old
Condition
Good
inspected August 2023
Type
Tee Beam
Concrete Continuous
Length
162 ft
3 main spans
Daily traffic
15,658
2023 count
Owner
State
State Highway Agency

About this bridge

I-90 over Umptanum RD is a concrete continuous tee beam carrying I-90 over Umptanum RD in Kittitas County, Washington. It was built in 1967, so it is 58 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 15,658 vehicles a day, roughly 23% of them trucks, projected to reach 19,097 by 2039. The structure is 162 ft (49.4 m) long and 41 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

CarriesI-90
CrossesUmptanum RD
Location2.2 E JCT US 97
RouteInterstate 90
Coordinates46.98094, -120.56064
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 inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating37.5 US tons
Inventory rating28.9 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20 + Mod
Structure length162 ft (49.4 m)
Longest span56 ft (17.1 m)
Deck width41 ft (12.6 m)
Roadway width38 ft (11.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic15,658 (2023)
Projected traffic19,097 by 2039
Trucks23%
Lanes on structure2
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 proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$3.2 million (2022 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was I-90 over Umptanum RD built?

It was built in 1967, making it 58 years old in 2025.

What condition is I-90 over Umptanum RD 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 August 2023.

How much traffic does I-90 over Umptanum RD carry?

About 15,658 vehicles per day (2023 count), of which roughly 23% are trucks.

How long is I-90 over Umptanum RD?

The structure is 162 ft (49.4 m) long with a longest span of 56 ft (17.1 m) and a deck 41 ft wide.

Who owns I-90 over Umptanum RD?

It is owned by the State Highway Agency.