US Bridges

Morrison ST over Willamette River

FairPosted for load

Multnomah County, Oregon · Willamette River MP 12.8 · Structure no. 02758 000000000

Built
1958
67 years old
Condition
Fair
inspected March 2023
Type
Movable - Bascule
Steel
Length
760 ft
1 main span
Daily traffic
55,335
2020 count
Owner
County
County Highway Agency

About this bridge

Morrison ST over Willamette River is a steel movable - bascule carrying Morrison ST over Willamette River in Multnomah County, Oregon. It was built in 1958, so it is 67 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 5 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. Its operating status is: posted for load restriction.

It carries about 55,335 vehicles a day, roughly 10% of them trucks, projected to reach 82,867 by 2025. The structure is 760 ft (231.6 m) long and 90 ft wide. If it were closed, the detour would be 0.6 mi (1 km).

Location

Open in Google Maps
CarriesMorrison ST
CrossesWillamette River
LocationWillamette River MP 12.8
RouteCity Street 9350
CountyMultnomah County
StateOregon
Coordinates45.51773, -122.66929
Functional classUrban Minor Arterial

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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMarch 2023
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation3: Basically intolerable, requiring high priority of corrective action
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating21.8 US tons
Inventory rating16.8 US tons

Structure

Structure typeMovable - Bascule
MaterialSteel
DeckOther
Main spans1 (+2 approach)
Design loadHS 20
Structure length760 ft (231.6 m)
Longest span285 ft (86.9 m)
Deck width90 ft (27.4 m)
Roadway width69 ft (20.9 m)
Vertical clearance over deck17 ft (5.1 m)

Traffic and service

Average daily traffic55,335 (2020)
Projected traffic82,867 by 2025
Trucks10%
Lanes on structure6
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

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusPossibly eligible for the National Register; requires further investigation
Work proposedNone recorded
Estimated improvement cost—
NavigationNavigation control on waterway (bridge permit required)

Frequently asked questions

When was Morrison ST over Willamette River built?

It was built in 1958, making it 67 years old in 2025.

What condition is Morrison ST over Willamette 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 March 2023.

How much traffic does Morrison ST over Willamette River carry?

About 55,335 vehicles per day (2020 count), of which roughly 10% are trucks.

How long is Morrison ST over Willamette River?

The structure is 760 ft (231.6 m) long with a longest span of 285 ft (86.9 m) and a deck 90 ft wide.

Who owns Morrison ST over Willamette River?

It is owned by the County Highway Agency.