US Bridges

Avenue a over Necanicum River

Fair

Clatsop County, Oregon · City of Seaside · Structure no. 08909 000 00001

Built
1963
62 years old
Condition
Fair
inspected April 2023
Type
Slab
Prestressed Concrete
Length
169 ft
6 main spans
Daily traffic
7,315
2020 count
Owner
City
City or Municipal Highway Agency

About this bridge

Avenue a over Necanicum River is a prestressed concrete slab carrying Avenue a over Necanicum River in Clatsop County, Oregon. It was built in 1963, so it is 62 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 7,315 vehicles a day, roughly 10% of them trucks, projected to reach 7,660 by 2025. The structure is 169 ft (51.5 m) long and 48 ft wide. If it were closed, the detour would be 0.6 mi (1 km).

Location

Open in Google Maps
CarriesAvenue a
CrossesNecanicum River
LocationCity of Seaside
RouteCity Street C0000
CountyClatsop County
StateOregon
Coordinates45.99208, -123.9242
Functional classUrban Collector

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 protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating50 US tons
Inventory rating38.6 US tons

Structure

Structure typeSlab
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans6
Design loadUnknown
Structure length169 ft (51.5 m)
Longest span28 ft (8.5 m)
Deck width48 ft (14.6 m)
Roadway width36 ft (11 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic7,315 (2020)
Projected traffic7,660 by 2025
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed0.6 mi (1 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal 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 Avenue a over Necanicum River built?

It was built in 1963, making it 62 years old in 2025.

What condition is Avenue a over Necanicum River 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 April 2023.

How much traffic does Avenue a over Necanicum River carry?

About 7,315 vehicles per day (2020 count), of which roughly 10% are trucks.

How long is Avenue a over Necanicum River?

The structure is 169 ft (51.5 m) long with a longest span of 28 ft (8.5 m) and a deck 48 ft wide.

Who owns Avenue a over Necanicum River?

It is owned by the City or Municipal Highway Agency.