US Bridges

Mill Creek RD over Mill Creek

Good

Walla Walla County, Washington · 8.35 SE Isaacs Ave · Structure no. 089086000000000

Built
2019
6 years old
Condition
Good
inspected September 2024
Type
Tee Beam
Prestressed Concrete
Length
171 ft
2 main spans
Daily traffic
380
2024 count
Owner
County
County Highway Agency

About this bridge

Mill Creek RD over Mill Creek is a prestressed concrete tee beam carrying Mill Creek RD over Mill Creek in Walla Walla County, Washington. It was built in 2019, so it is 6 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 380 vehicles a day, roughly 10% of them trucks, projected to reach 560 by 2046. The structure is 171 ft (52.1 m) long and 34 ft wide. If it were closed, the detour would be 18 mi (29 km).

CarriesMill Creek RD
CrossesMill Creek
Location8.35 SE Isaacs Ave
RouteCounty Highway 97330
Coordinates46.0319, -118.14431
Functional classRural Major Collector

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 rating95 US tons
Inventory rating71.8 US tons

Structure

Structure typeTee Beam
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans2
Design loadHL 93
Structure length171 ft (52.1 m)
Longest span169 ft (51.4 m)
Deck width34 ft (10.5 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic380 (2024)
Projected traffic560 by 2046
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed18 mi (29 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$6.5 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Mill Creek RD over Mill Creek built?

It was built in 2019, making it 6 years old in 2025.

What condition is Mill Creek RD over Mill Creek 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 Mill Creek RD over Mill Creek carry?

About 380 vehicles per day (2024 count), of which roughly 10% are trucks.

How long is Mill Creek RD over Mill Creek?

The structure is 171 ft (52.1 m) long with a longest span of 169 ft (51.4 m) and a deck 34 ft wide.

Who owns Mill Creek RD over Mill Creek?

It is owned by the County Highway Agency.