US Bridges

SUNSET/3360 over Thorn Creek

Good

Whitman County, Washington · 12.27 MI NE Pne Cty-Maldn · Structure no. 089076000000000

Built
2019
6 years old
Condition
Good
inspected August 2023
Type
Slab
Prestressed Concrete
Length
34 ft
1 main span
Daily traffic
70
2019 count
Owner
County
County Highway Agency

About this bridge

SUNSET/3360 over Thorn Creek is a prestressed concrete slab carrying SUNSET/3360 over Thorn Creek in Whitman 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 70 vehicles a day, roughly 25% of them trucks, projected to reach 70 by 2040. The structure is 34 ft (10.4 m) long and 32 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesSUNSET/3360
CrossesThorn Creek
Location12.27 MI NE Pne Cty-Maldn
RouteCounty Highway 33600
CountyWhitman County
StateWashington
Coordinates47.11943, -117.39162
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 inspectionAugust 2023
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 rating63.2 US tons
Inventory rating37.1 US tons

Structure

Structure typeSlab
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans1
Design loadGreater than HL 93
Structure length34 ft (10.4 m)
Longest span33 ft (10.1 m)
Deck width32 ft (9.8 m)
Roadway width31 ft (9.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic70 (2019)
Projected traffic70 by 2040
Trucks25%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 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$1.6 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SUNSET/3360 over Thorn Creek built?

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

What condition is SUNSET/3360 over Thorn 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 August 2023.

How much traffic does SUNSET/3360 over Thorn Creek carry?

About 70 vehicles per day (2019 count), of which roughly 25% are trucks.

How long is SUNSET/3360 over Thorn Creek?

The structure is 34 ft (10.4 m) long with a longest span of 33 ft (10.1 m) and a deck 32 ft wide.

Who owns SUNSET/3360 over Thorn Creek?

It is owned by the County Highway Agency.