US Bridges

Road over Dingford Creek

Fair

King County, Washington · 5.8 MI E of 56/5640 JCT · Structure no. 060505000001533

Built
1961
64 years old
Condition
Fair
inspected July 2021
Type
Stringer/Multi-beam or Girder
Steel
Length
48 ft
1 main span
Daily traffic
45
1995 count
Owner
Federal
U.S. Forest Service

About this bridge

Road over Dingford Creek is a steel stringer/multi-beam or girder carrying Road over Dingford Creek in King County, Washington. It was built in 1961, so it is 64 years old, older than the Washington average of 49.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 45 vehicles a day, projected to reach 67 by 2045. The structure is 48 ft (14.5 m) long and 22 ft wide. If it were closed, the detour would be 98.2 mi (158 km).

Location

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CarriesRoad
CrossesDingford Creek
Location5.8 MI E of 56/5640 JCT
RouteFederal Lands Road 56
CountyKing County
StateWashington
Coordinates47.51667, -121.45
Functional classRural Local

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJuly 2021
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to 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 alignment6: Equal to present minimum criteria
Operating rating56 US tons
Inventory rating36 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadOther
Structure length48 ft (14.5 m)
Longest span45 ft (13.7 m)
Deck width22 ft (6.7 m)
Roadway width20 ft (6.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic45 (1995)
Projected traffic67 by 2045
Trucks—
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed98.2 mi (158 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerU.S. Forest Service
Maintained byU.S. Forest Service
Historic statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Road over Dingford Creek built?

It was built in 1961, making it 64 years old in 2025.

What condition is Road over Dingford Creek in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in July 2021.

How much traffic does Road over Dingford Creek carry?

About 45 vehicles per day (1995 count).

How long is Road over Dingford Creek?

The structure is 48 ft (14.5 m) long with a longest span of 45 ft (13.7 m) and a deck 22 ft wide.

Who owns Road over Dingford Creek?

It is owned by the U.S. Forest Service.