US Bridges

SW 6th AVE(CONN3) over I-405 (hwy 61)

Fair

Multnomah County, Oregon · 0.4 MI S of SW 12th Ave · Structure no. 09158 061C00102

Built
1964
61 years old
Condition
Fair
inspected July 2023
Type
Box Beam or Girders - Multiple
Concrete Continuous
Length
267 ft
4 main spans
Daily traffic
19,585
2022 count
Owner
State
State Highway Agency

About this bridge

SW 6th AVE(CONN3) over I-405 (hwy 61) is a concrete continuous box beam or girders - multiple carrying SW 6th AVE(CONN3) over I-405 (hwy 61) in Multnomah County, Oregon. It was built in 1964, so it is 61 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.

It carries about 19,585 vehicles a day, roughly 6% of them trucks, projected to reach 95,500 by 2040. The structure is 267 ft (81.4 m) long and 51 ft wide. If it were closed, the detour would be 4.3 mi (7 km).

Location

Open in Google Maps
CarriesSW 6th AVE(CONN3)
CrossesI-405 (hwy 61)
Location0.4 MI S of SW 12th Ave
RouteInterstate 405
CountyMultnomah County
StateOregon
Coordinates45.50778, -122.68426
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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Approach roadway alignment7: Better than present minimum criteria
Operating rating25 US tons
Inventory rating19.3 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadH 20
Structure length267 ft (81.4 m)
Longest span84 ft (25.6 m)
Deck width51 ft (15.4 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic19,585 (2022)
Projected traffic95,500 by 2040
Trucks6%
Lanes on structure3
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesHighway
Detour if closed4.3 mi (7 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 proposedWidening of existing bridge without deck rehabilitation
Estimated improvement cost$2.2 million
NavigationNot applicable (no waterway)

Frequently asked questions

When was SW 6th AVE(CONN3) over I-405 (hwy 61) built?

It was built in 1964, making it 61 years old in 2025.

What condition is SW 6th AVE(CONN3) over I-405 (hwy 61) 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 2023.

How much traffic does SW 6th AVE(CONN3) over I-405 (hwy 61) carry?

About 19,585 vehicles per day (2022 count), of which roughly 6% are trucks.

How long is SW 6th AVE(CONN3) over I-405 (hwy 61)?

The structure is 267 ft (81.4 m) long with a longest span of 84 ft (25.6 m) and a deck 51 ft wide.

Who owns SW 6th AVE(CONN3) over I-405 (hwy 61)?

It is owned by the State Highway Agency.