US Bridges

SR 27 over Missouri Flat CR

Fair

Whitman County, Washington · 0.3 N JCT SR 270 · Structure no. 0004989A0000000

Built
1955
70 years old
Condition
Fair
inspected September 2023
Type
Slab
Concrete
Length
64 ft
1 main span
Daily traffic
17,702
2023 count
Owner
State
State Highway Agency

About this bridge

SR 27 over Missouri Flat CR is a concrete slab carrying SR 27 over Missouri Flat CR in Whitman County, Washington. It was built in 1955, so it is 70 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 17,702 vehicles a day, roughly 2% of them trucks, projected to reach 20,639 by 2039. The structure is 64 ft (19.5 m) long and 57 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesSR 27
CrossesMissouri Flat CR
Location0.3 N JCT SR 270
RouteState Highway 27
CountyWhitman County
StateWashington
Coordinates46.73439, -117.17756
Functional classUrban Other Principal Arterial

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating70 US tons
Inventory rating42 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length64 ft (19.5 m)
Longest span59 ft (18 m)
Deck width57 ft (17.4 m)
Roadway width44 ft (13.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic17,702 (2023)
Projected traffic20,639 by 2039
Trucks2%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes

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$1.4 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SR 27 over Missouri Flat CR built?

It was built in 1955, making it 70 years old in 2025.

What condition is SR 27 over Missouri Flat CR 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 27 over Missouri Flat CR carry?

About 17,702 vehicles per day (2023 count), of which roughly 2% are trucks.

How long is SR 27 over Missouri Flat CR?

The structure is 64 ft (19.5 m) long with a longest span of 59 ft (18 m) and a deck 57 ft wide.

Who owns SR 27 over Missouri Flat CR?

It is owned by the State Highway Agency.