US Bridges

Grand Island Road over Mosquito Creek

Fair

Yamhill County, Oregon · 700 M S Dayton · Structure no. 11783 000

Built
1976
49 years old
Condition
Fair
inspected September 2024
Type
Slab
Prestressed Concrete
Length
139 ft
3 main spans
Daily traffic
242
2020 count
Owner
County
County Highway Agency

About this bridge

Grand Island Road over Mosquito Creek is a prestressed concrete slab carrying Grand Island Road over Mosquito Creek in Yamhill County, Oregon. It was built in 1976, so it is 49 years old, younger than the Oregon average of 49.9 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 242 vehicles a day, roughly 10% of them trucks, projected to reach 272 by 2025. The structure is 139 ft (42.4 m) long and 32 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesGrand Island Road
CrossesMosquito Creek
Location700 M S Dayton
RouteCounty Highway C0029
CountyYamhill County
StateOregon
Coordinates45.12955, -123.03509
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
Deck8 Very GoodNo problems noted.
Superstructure8 Very GoodNo problems noted.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionSeptember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating25.4 US tons
Inventory rating19.6 US tons

Structure

Structure typeSlab
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length139 ft (42.4 m)
Longest span48 ft (14.6 m)
Deck width32 ft (9.8 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic242 (2020)
Projected traffic272 by 2025
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Grand Island Road over Mosquito Creek built?

It was built in 1976, making it 49 years old in 2025.

What condition is Grand Island Road over Mosquito 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 September 2024.

How much traffic does Grand Island Road over Mosquito Creek carry?

About 242 vehicles per day (2020 count), of which roughly 10% are trucks.

How long is Grand Island Road over Mosquito Creek?

The structure is 139 ft (42.4 m) long with a longest span of 48 ft (14.6 m) and a deck 32 ft wide.

Who owns Grand Island Road over Mosquito Creek?

It is owned by the County Highway Agency.