US Bridges

SR 278 over Rock Creek

Fair

Spokane County, Washington · 0.4 E JCT SR 27 · Structure no. 085485000000000

Built
1920
105 years old, rebuilt 1989
Condition
Fair
inspected September 2023
Type
Arch - Deck
Concrete Continuous
Length
99 ft
2 main spans
Daily traffic
4,017
2023 count
Owner
State
State Highway Agency

About this bridge

SR 278 over Rock Creek is a concrete continuous arch - deck carrying SR 278 over Rock Creek in Spokane County, Washington. It was built in 1920 and reconstructed in 1989, so it is 105 years old, older than the Washington average of 49.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 4,017 vehicles a day, roughly 9% of them trucks, projected to reach 5,166 by 2039. The structure is 99 ft (30.2 m) long and 45 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

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CarriesSR 278
CrossesRock Creek
Location0.4 E JCT SR 27
RouteState Highway 278
CountySpokane County
StateWashington
Coordinates47.45219, -117.13486
Functional classRural Major Collector

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating50.7 US tons
Inventory rating38.9 US tons

Structure

Structure typeArch - Deck
MaterialConcrete Continuous
DeckNot applicable
Main spans2
Design loadHS 20
Structure length99 ft (30.2 m)
Longest span47 ft (14.3 m)
Deck width45 ft (13.6 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,017 (2023)
Projected traffic5,166 by 2039
Trucks9%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed6.2 mi (10 km)
TollOn a free road
National Highway SystemNo

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$1.6 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SR 278 over Rock Creek built?

It was built in 1920, making it 105 years old in 2025. It was reconstructed in 1989.

What condition is SR 278 over Rock Creek in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in September 2023.

How much traffic does SR 278 over Rock Creek carry?

About 4,017 vehicles per day (2023 count), of which roughly 9% are trucks.

How long is SR 278 over Rock Creek?

The structure is 99 ft (30.2 m) long with a longest span of 47 ft (14.3 m) and a deck 45 ft wide.

Who owns SR 278 over Rock Creek?

It is owned by the State Highway Agency.