US Bridges

HWY 1 Conn #1 over HWY 51 NB

Fair

Clackamas County, Oregon · 021 MI N Marion-Clack LN · Structure no. 09870 001 28243

Built
1971
54 years old
Condition
Fair
inspected August 2024
Type
Box Beam or Girders - Multiple
Concrete Continuous
Length
313 ft
3 main spans
Daily traffic
63,616
2022 count
Owner
State
State Highway Agency

About this bridge

HWY 1 Conn #1 over HWY 51 NB is a concrete continuous box beam or girders - multiple carrying HWY 1 Conn #1 over HWY 51 NB in Clackamas County, Oregon. It was built in 1971, so it is 54 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 63,616 vehicles a day, roughly 13% of them trucks, projected to reach 77,500 by 2042. The structure is 313 ft (95.4 m) long and 31 ft wide. If it were closed, the detour would be 12.4 mi (20 km).

Location

Open in Google Maps
CarriesHWY 1 Conn #1
CrossesHWY 51 NB
Location021 MI N Marion-Clack LN
RouteState Highway 5
CountyClackamas County
StateOregon
Coordinates45.28179, -122.76857
Functional classRural 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 inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating47.2 US tons
Inventory rating36.4 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length313 ft (95.4 m)
Longest span144 ft (43.9 m)
Deck width31 ft (9.6 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic63,616 (2022)
Projected traffic77,500 by 2042
Trucks13%
Lanes on structure1
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed12.4 mi (20 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

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 HWY 1 Conn #1 over HWY 51 NB built?

It was built in 1971, making it 54 years old in 2025.

What condition is HWY 1 Conn #1 over HWY 51 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 August 2024.

How much traffic does HWY 1 Conn #1 over HWY 51 NB carry?

About 63,616 vehicles per day (2022 count), of which roughly 13% are trucks.

How long is HWY 1 Conn #1 over HWY 51 NB?

The structure is 313 ft (95.4 m) long with a longest span of 144 ft (43.9 m) and a deck 31 ft wide.

Who owns HWY 1 Conn #1 over HWY 51 NB?

It is owned by the State Highway Agency.