US Bridges

I-90 over Coal Creek

Poor

Kittitas County, Washington · 0.5 E JCT SR 906 · Structure no. 0005203A0000000

Built
1956
69 years old, rebuilt 1972
Condition
Poor
inspected July 2023
Type
Frame
Concrete
Length
57 ft
1 main span
Daily traffic
18,069
2023 count
Owner
State
State Highway Agency

About this bridge

I-90 over Coal Creek is a concrete frame carrying I-90 over Coal Creek in Kittitas County, Washington. It was built in 1956 and reconstructed in 1972, so it is 69 years old, older than the Washington average of 49.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

It carries about 18,069 vehicles a day, roughly 21% of them trucks, projected to reach 22,265 by 2039. The structure is 57 ft (17.4 m) long and 54 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesI-90
CrossesCoal Creek
Location0.5 E JCT SR 906
RouteInterstate 90
CountyKittitas County
StateWashington
Coordinates47.39319, -121.38947
Functional classRural Principal Arterial - Interstate

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck4 PoorAdvanced section loss, deterioration, spalling or scour.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation7: Better than present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating45.3 US tons
Inventory rating35.1 US tons

Structure

Structure typeFrame
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length57 ft (17.4 m)
Longest span54 ft (16.5 m)
Deck width54 ft (16.6 m)
Roadway width52 ft (15.8 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 statusNot eligible for the National Register of Historic Places
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$1.5 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was I-90 over Coal Creek built?

It was built in 1956, making it 69 years old in 2025. It was reconstructed in 1972.

What condition is I-90 over Coal Creek in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in July 2023.

How much traffic does I-90 over Coal Creek carry?

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

How long is I-90 over Coal Creek?

The structure is 57 ft (17.4 m) long with a longest span of 54 ft (16.5 m) and a deck 54 ft wide.

Who owns I-90 over Coal Creek?

It is owned by the State Highway Agency.