US Bridges

SR 23 over Rock Creek

Poor

Whitman County, Washington · 23.2 N JCT US 195 · Structure no. 0003122B0000000

Built
1946
79 years old
Condition
Poor
inspected September 2023
Type
Tee Beam
Concrete Continuous
Length
132 ft
3 main spans
Daily traffic
269
2023 count
Owner
State
State Highway Agency

About this bridge

SR 23 over Rock Creek is a concrete continuous tee beam carrying SR 23 over Rock Creek in Whitman County, Washington. It was built in 1946, so it is 79 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 3 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 269 vehicles a day, roughly 22% of them trucks, projected to reach 281 by 2039. The structure is 132 ft (40.2 m) long and 33 ft wide. If it were closed, the detour would be 13 mi (21 km).

Location

Open in Google Maps
CarriesSR 23
CrossesRock Creek
Location23.2 N JCT US 195
RouteState Highway 23
CountyWhitman County
StateWashington
Coordinates47.124, -117.75022
Functional classRural Major Collector

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
Deck3 SeriousLoss of section, deterioration, spalling or scour have seriously affected primary structural components.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
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 geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating46 US tons
Inventory rating27 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 15
Structure length132 ft (40.2 m)
Longest span50 ft (15.2 m)
Deck width33 ft (10.2 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic269 (2023)
Projected traffic281 by 2039
Trucks22%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed13 mi (21 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$1.8 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SR 23 over Rock Creek built?

It was built in 1946, making it 79 years old in 2025.

What condition is SR 23 over Rock 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 September 2023.

How much traffic does SR 23 over Rock Creek carry?

About 269 vehicles per day (2023 count), of which roughly 22% are trucks.

How long is SR 23 over Rock Creek?

The structure is 132 ft (40.2 m) long with a longest span of 50 ft (15.2 m) and a deck 33 ft wide.

Who owns SR 23 over Rock Creek?

It is owned by the State Highway Agency.