US Bridges

Day Island Road over Patterson Slough

Fair

Lane County, Oregon · 015 MI W I5-I105 Intersec · Structure no. 39C141150300018

Built
1984
41 years old
Condition
Fair
inspected May 2023
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
94 ft
3 main spans
Daily traffic
3,744
2020 count
Owner
City
City or Municipal Highway Agency

About this bridge

Day Island Road over Patterson Slough is a wood or timber stringer/multi-beam or girder carrying Day Island Road over Patterson Slough in Lane County, Oregon. It was built in 1984, so it is 41 years old, younger 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 3,744 vehicles a day, roughly 1% of them trucks, projected to reach 4,277 by 2025. The structure is 94 ft (28.7 m) long and 28 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

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CarriesDay Island Road
CrossesPatterson Slough
Location015 MI W I5-I105 Intersec
RouteCity Street C1503
CountyLane County
StateOregon
Coordinates44.05703, -123.08102
Functional classUrban Local

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.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating53.6 US tons
Inventory rating41.4 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length94 ft (28.7 m)
Longest span37 ft (11.3 m)
Deck width28 ft (8.5 m)
Roadway width27 ft (8.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,744 (2020)
Projected traffic4,277 by 2025
Trucks1%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed123.7 mi (199 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedWidening of existing bridge without deck rehabilitation
Estimated improvement cost$482,000
NavigationNo navigation control on waterway

Frequently asked questions

When was Day Island Road over Patterson Slough built?

It was built in 1984, making it 41 years old in 2025.

What condition is Day Island Road over Patterson Slough 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 May 2023.

How much traffic does Day Island Road over Patterson Slough carry?

About 3,744 vehicles per day (2020 count), of which roughly 1% are trucks.

How long is Day Island Road over Patterson Slough?

The structure is 94 ft (28.7 m) long with a longest span of 37 ft (11.3 m) and a deck 28 ft wide.

Who owns Day Island Road over Patterson Slough?

It is owned by the City or Municipal Highway Agency.