US Bridges

BLACKWELL/4470 over Branch Dry Creek

Good

Whitman County, Washington · 3.00 Mi. SE Green Hollow · Structure no. 087990000000000

Built
2009
16 years old
Condition
Good
inspected August 2023
Type
Slab
Prestressed Concrete
Length
25 ft
1 main span
Daily traffic
50
2020 count
Owner
County
County Highway Agency

About this bridge

BLACKWELL/4470 over Branch Dry Creek is a prestressed concrete slab carrying BLACKWELL/4470 over Branch Dry Creek in Whitman County, Washington. It was built in 2009, so it is 16 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 50 vehicles a day, roughly 25% of them trucks, projected to reach 31 by 2039. The structure is 25 ft (7.6 m) long and 28 ft wide. If it were closed, the detour would be 8.1 mi (13 km).

Location

Open in Google Maps
CarriesBLACKWELL/4470
CrossesBranch Dry Creek
Location3.00 Mi. SE Green Hollow
RouteCounty Highway 44700
CountyWhitman County
StateWashington
Coordinates46.98455, -117.36835
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
Deck7 GoodSome minor problems.
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 evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating31.4 US tons
Inventory rating20.7 US tons

Structure

Structure typeSlab
MaterialPrestressed Concrete
DeckOther
Main spans1
Design loadHS 20
Structure length25 ft (7.6 m)
Longest span24 ft (7.3 m)
Deck width28 ft (8.5 m)
Roadway width28 ft (8.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic50 (2020)
Projected traffic31 by 2039
Trucks25%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed8.1 mi (13 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$1.3 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was BLACKWELL/4470 over Branch Dry Creek built?

It was built in 2009, making it 16 years old in 2025.

What condition is BLACKWELL/4470 over Branch Dry 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 BLACKWELL/4470 over Branch Dry Creek carry?

About 50 vehicles per day (2020 count), of which roughly 25% are trucks.

How long is BLACKWELL/4470 over Branch Dry Creek?

The structure is 25 ft (7.6 m) long with a longest span of 24 ft (7.3 m) and a deck 28 ft wide.

Who owns BLACKWELL/4470 over Branch Dry Creek?

It is owned by the County Highway Agency.