US Bridges

Gnat Creek Road over Gnat Creek

Fair

Clatsop County, Oregon · 0.2MI from US-30 · Structure no. 21002 000 00000

Built
1960
65 years old
Condition
Fair
inspected July 2024
Type
Slab
Prestressed Concrete
Length
34 ft
1 main span
Daily traffic
30
2010 count
Owner
State
State Park, Forest, or Reservation Agency

About this bridge

Gnat Creek Road over Gnat Creek is a prestressed concrete slab carrying Gnat Creek Road over Gnat Creek in Clatsop County, Oregon. It was built in 1960, so it is 65 years old, older 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 30 vehicles a day, roughly 1% of them trucks, projected to reach 36 by 2030. The structure is 34 ft (10.4 m) long and 16 ft wide.

Location

Open in Google Maps
CarriesGnat Creek Road
CrossesGnat Creek
Location0.2MI from US-30
RouteState Lands Road 0
CountyClatsop County
StateOregon
Coordinates46.17703, -123.50312
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 protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionJuly 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; action required to protect exposed foundations
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 rating99 US tons
Inventory rating61 US tons

Structure

Structure typeSlab
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans1
Design loadHS 20
Structure length34 ft (10.4 m)
Longest span34 ft (10.4 m)
Deck width16 ft (4.9 m)
Roadway width15 ft (4.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic30 (2010)
Projected traffic36 by 2030
Trucks1%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed—
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Park, Forest, or Reservation Agency
Maintained byState Park, Forest, or Reservation 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 Gnat Creek Road over Gnat Creek built?

It was built in 1960, making it 65 years old in 2025.

What condition is Gnat Creek Road over Gnat 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 2024.

How much traffic does Gnat Creek Road over Gnat Creek carry?

About 30 vehicles per day (2010 count), of which roughly 1% are trucks.

How long is Gnat Creek Road over Gnat Creek?

The structure is 34 ft (10.4 m) long with a longest span of 34 ft (10.4 m) and a deck 16 ft wide.

Who owns Gnat Creek Road over Gnat Creek?

It is owned by the State Park, Forest, or Reservation Agency.