US Bridges

Hy 1SB to Hy 61NB over Marq Ramp to HWY 61 NB

Fair

Multnomah County, Oregon · West Marquam Interchange · Structure no. 08591B001C30046

Built
1965
60 years old
Condition
Fair
inspected September 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
1,608 ft
11 main spans
Daily traffic
24,925
2022 count
Owner
State
State Highway Agency

About this bridge

Hy 1SB to Hy 61NB over Marq Ramp to HWY 61 NB is a steel stringer/multi-beam or girder carrying Hy 1SB to Hy 61NB over Marq Ramp to HWY 61 NB in Multnomah County, Oregon. It was built in 1965, so it is 60 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 24,925 vehicles a day, roughly 10% of them trucks, projected to reach 77,550 by 2040. The structure is 1,608 ft (490 m) long and 37 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

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CarriesHy 1SB to Hy 61NB
CrossesMarq Ramp to HWY 61 NB
LocationWest Marquam Interchange
RouteInterstate 5
CountyMultnomah County
StateOregon
Coordinates45.50542, -122.67536
Functional classUrban Principal Arterial - Interstate

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.
Last inspectionSeptember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation3: Basically intolerable, requiring high priority of corrective action
Deck geometry6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating18.2 US tons
Inventory rating13.9 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans11 (+4 approach)
Design loadHS 20
Structure length1,608 ft (490 m)
Longest span178 ft (54.4 m)
Deck width37 ft (11.3 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deck19 ft (5.6 m)

Traffic and service

Average daily traffic24,925 (2022)
Projected traffic77,550 by 2040
Trucks10%
Lanes on structure2
Traffic directionOne-way traffic
CarriesOverpass structure at an interchange
CrossesHighway
Detour if closed6.2 mi (10 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was Hy 1SB to Hy 61NB over Marq Ramp to HWY 61 NB built?

It was built in 1965, making it 60 years old in 2025.

What condition is Hy 1SB to Hy 61NB over Marq Ramp to HWY 61 NB 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 Hy 1SB to Hy 61NB over Marq Ramp to HWY 61 NB carry?

About 24,925 vehicles per day (2022 count), of which roughly 10% are trucks.

How long is Hy 1SB to Hy 61NB over Marq Ramp to HWY 61 NB?

The structure is 1,608 ft (490 m) long with a longest span of 178 ft (54.4 m) and a deck 37 ft wide.

Who owns Hy 1SB to Hy 61NB over Marq Ramp to HWY 61 NB?

It is owned by the State Highway Agency.