US Bridges

Byrnes RD over Nine Mile Canyon

Fair

Walla Walla County, Washington · 00.13 E SR 12(W) · Structure no. 083071000000000

Built
1916
109 years old
Condition
Fair
inspected September 2023
Type
Other
Concrete
Length
45 ft
1 main span
Daily traffic
30
2021 count
Owner
County
County Highway Agency

About this bridge

Byrnes RD over Nine Mile Canyon is a concrete other carrying Byrnes RD over Nine Mile Canyon in Walla Walla County, Washington. It was built in 1916, so it is 109 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 5 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 30 vehicles a day, roughly 10% of them trucks, projected to reach 40 by 2041. The structure is 45 ft (13.7 m) long and 22 ft wide. If it were closed, the detour would be 14.9 mi (24 km).

Location

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CarriesByrnes RD
CrossesNine Mile Canyon
Location00.13 E SR 12(W)
RouteCounty Highway 17080
CountyWalla Walla County
StateWashington
Coordinates46.07083, -118.78222
Functional classRural Minor 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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
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 evaluation2: Basically intolerable, requiring high priority of replacement
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating20 US tons
Inventory rating10 US tons

Structure

Structure typeOther
MaterialConcrete
DeckNot applicable
Main spans1
Design loadH 10
Structure length45 ft (13.7 m)
Longest span45 ft (13.7 m)
Deck width22 ft (6.8 m)
Roadway width20 ft (6.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic30 (2021)
Projected traffic40 by 2041
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesRelief for waterway
Detour if closed14.9 mi (24 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$2 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Byrnes RD over Nine Mile Canyon built?

It was built in 1916, making it 109 years old in 2025.

What condition is Byrnes RD over Nine Mile Canyon 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 Byrnes RD over Nine Mile Canyon carry?

About 30 vehicles per day (2021 count), of which roughly 10% are trucks.

How long is Byrnes RD over Nine Mile Canyon?

The structure is 45 ft (13.7 m) long with a longest span of 45 ft (13.7 m) and a deck 22 ft wide.

Who owns Byrnes RD over Nine Mile Canyon?

It is owned by the County Highway Agency.