US Bridges

SR 505 over Mill Creek

Good

Lewis County, Washington · 1.3 E JCT I-5 · Structure no. 080476000000000

Built
1984
41 years old
Condition
Good
inspected November 2021
Type
Slab
Concrete Continuous
Length
57 ft
2 main spans
Daily traffic
3,782
2023 count
Owner
State
State Highway Agency

About this bridge

SR 505 over Mill Creek is a concrete continuous slab carrying SR 505 over Mill Creek in Lewis County, Washington. It was built in 1984, so it is 41 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 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 3,782 vehicles a day, roughly 8% of them trucks, projected to reach 4,599 by 2039. The structure is 57 ft (17.4 m) long and 37 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

Open in Google Maps
CarriesSR 505
CrossesMill Creek
Location1.3 E JCT I-5
RouteState Highway 505
CountyLewis County
StateWashington
Coordinates46.46881, -122.85793
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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionNovember 2021
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation7: Better than present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating63.9 US tons
Inventory rating39 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20
Structure length57 ft (17.4 m)
Longest span28 ft (8.5 m)
Deck width37 ft (11.3 m)
Roadway width34 ft (10.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,782 (2023)
Projected traffic4,599 by 2039
Trucks8%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 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 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SR 505 over Mill Creek built?

It was built in 1984, making it 41 years old in 2025.

What condition is SR 505 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 November 2021.

How much traffic does SR 505 over Mill Creek carry?

About 3,782 vehicles per day (2023 count), of which roughly 8% are trucks.

How long is SR 505 over Mill Creek?

The structure is 57 ft (17.4 m) long with a longest span of 28 ft (8.5 m) and a deck 37 ft wide.

Who owns SR 505 over Mill Creek?

It is owned by the State Highway Agency.