US Bridges

Detour RD over Walla Walla River

Good

Walla Walla County, Washington · 0.066 S of SR 12 · Structure no. 086822000000000

Built
2002
23 years old
Condition
Good
inspected September 2024
Type
Tee Beam
Prestressed Concrete
Length
200 ft
2 main spans
Daily traffic
664
2024 count
Owner
County
County Highway Agency

About this bridge

Detour RD over Walla Walla River is a prestressed concrete tee beam carrying Detour RD over Walla Walla River in Walla Walla County, Washington. It was built in 2002, so it is 23 years old, younger than the Washington average of 49.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 8 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 664 vehicles a day, roughly 40% of them trucks, projected to reach 810 by 2046. The structure is 200 ft (61 m) long and 39 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

CarriesDetour RD
CrossesWalla Walla River
Location0.066 S of SR 12
RouteCounty Highway 20840
Coordinates46.04279, -118.49084
Functional classRural Local

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionSeptember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation8: Equal to present desirable criteria
Deck geometry7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating59 US tons
Inventory rating41.1 US tons

Structure

Structure typeTee Beam
MaterialPrestressed Concrete
DeckOther
Main spans2
Design loadHS 25 or greater
Structure length200 ft (61 m)
Longest span100 ft (30.5 m)
Deck width39 ft (11.9 m)
Roadway width36 ft (11 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic664 (2024)
Projected traffic810 by 2046
Trucks40%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$7.6 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Detour RD over Walla Walla River built?

It was built in 2002, making it 23 years old in 2025.

What condition is Detour RD over Walla Walla River in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in September 2024.

How much traffic does Detour RD over Walla Walla River carry?

About 664 vehicles per day (2024 count), of which roughly 40% are trucks.

How long is Detour RD over Walla Walla River?

The structure is 200 ft (61 m) long with a longest span of 100 ft (30.5 m) and a deck 39 ft wide.

Who owns Detour RD over Walla Walla River?

It is owned by the County Highway Agency.