US Bridges

Larkin Road over Drainage Ditch

GoodPosted for load

Pacific County, Washington · 3.7 S Gray Har CO · Structure no. 084347000000000

Built
1986
39 years old
Condition
Good
inspected June 2024
Type
Slab
Concrete Continuous
Length
55 ft
2 main spans
Daily traffic
58
2023 count
Owner
County
County Highway Agency

About this bridge

Larkin Road over Drainage Ditch is a concrete continuous slab carrying Larkin Road over Drainage Ditch in Pacific County, Washington. It was built in 1986, so it is 39 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. Its operating status is: posted for load restriction.

It carries about 58 vehicles a day, projected to reach 100 by 2043. The structure is 55 ft (16.8 m) long and 29 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

CarriesLarkin Road
CrossesDrainage Ditch
Location3.7 S Gray Har CO
RouteCounty Highway 51510
Coordinates46.74092, -124.07211
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.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJune 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating30.8 US tons
Inventory rating23.6 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20
Structure length55 ft (16.8 m)
Longest span27 ft (8.2 m)
Deck width29 ft (8.8 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic58 (2023)
Projected traffic100 by 2043
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedOther structural work, including hydraulic replacements
Estimated improvement cost$522,000 (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Larkin Road over Drainage Ditch built?

It was built in 1986, making it 39 years old in 2025.

What condition is Larkin Road over Drainage Ditch 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 June 2024.

How much traffic does Larkin Road over Drainage Ditch carry?

About 58 vehicles per day (2023 count).

How long is Larkin Road over Drainage Ditch?

The structure is 55 ft (16.8 m) long with a longest span of 27 ft (8.2 m) and a deck 29 ft wide.

Who owns Larkin Road over Drainage Ditch?

It is owned by the County Highway Agency.