US Bridges

Four Mile Creek over MADER/5170

Good

Whitman County, Washington · Four Mile Creek · Structure no. 088251000000000

Built
2010
15 years old
Condition
Good
inspected January 2023
Type
Slab
Prestressed Concrete
Length
25 ft
1 main span
Daily traffic
20
2021 count
Owner
County
County Highway Agency

About this bridge

Four Mile Creek over MADER/5170 is a prestressed concrete slab carrying Four Mile Creek over MADER/5170 in Whitman County, Washington. It was built in 2010, so it is 15 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 20 vehicles a day, roughly 25% of them trucks, projected to reach 21 by 2042. The structure is 25 ft (7.6 m) long and 28 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

CarriesFour Mile Creek
CrossesMADER/5170
LocationFour Mile Creek
RouteCounty Highway 51700
Coordinates46.87368, -117.07392
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 inspectionJanuary 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 span23 ft (7 m)
Deck width28 ft (8.5 m)
Roadway width28 ft (8.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic20 (2021)
Projected traffic21 by 2042
Trucks25%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 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 Four Mile Creek over MADER/5170 built?

It was built in 2010, making it 15 years old in 2025.

What condition is Four Mile Creek over MADER/5170 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 January 2023.

How much traffic does Four Mile Creek over MADER/5170 carry?

About 20 vehicles per day (2021 count), of which roughly 25% are trucks.

How long is Four Mile Creek over MADER/5170?

The structure is 25 ft (7.6 m) long with a longest span of 23 ft (7 m) and a deck 28 ft wide.

Who owns Four Mile Creek over MADER/5170?

It is owned by the County Highway Agency.