US Bridges

SR 506 over Lacamas Creek

Good

Lewis County, Washington · 7.0 E Cowlitz CO · Structure no. 0019419A0000000

Built
2020
5 years old
Condition
Good
inspected November 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
175 ft
1 main span
Daily traffic
2,095
2023 count
Owner
State
State Highway Agency

About this bridge

SR 506 over Lacamas Creek is a prestressed concrete stringer/multi-beam or girder carrying SR 506 over Lacamas Creek in Lewis County, Washington. It was built in 2020, so it is 5 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 2,095 vehicles a day, roughly 6% of them trucks, projected to reach 2,446 by 2038. The structure is 175 ft (53.3 m) long and 35 ft wide. If it were closed, the detour would be 6.8 mi (11 km).

CarriesSR 506
CrossesLacamas Creek
Location7.0 E Cowlitz CO
RouteState Highway 506
Coordinates46.41175, -122.92619
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 inspectionNovember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation8: Equal to present desirable criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating79.7 US tons
Inventory rating51 US tons

Structure

MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHL 93
Structure length175 ft (53.3 m)
Longest span169 ft (51.5 m)
Deck width35 ft (10.7 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,095 (2023)
Projected traffic2,446 by 2038
Trucks6%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.8 mi (11 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$2.8 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SR 506 over Lacamas Creek built?

It was built in 2020, making it 5 years old in 2025.

What condition is SR 506 over Lacamas 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 2024.

How much traffic does SR 506 over Lacamas Creek carry?

About 2,095 vehicles per day (2023 count), of which roughly 6% are trucks.

How long is SR 506 over Lacamas Creek?

The structure is 175 ft (53.3 m) long with a longest span of 169 ft (51.5 m) and a deck 35 ft wide.

Who owns SR 506 over Lacamas Creek?

It is owned by the State Highway Agency.