US Bridges

US101 (hwy 9) over Slide Viaduct

Fair

Lane County, Oregon · 11.5 MI N HWY 062 JCT · Structure no. 01741B009 17875

Built
1962
63 years old
Condition
Fair
inspected July 2023
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
143 ft
2 main spans
Daily traffic
3,187
2022 count
Owner
State
State Highway Agency

About this bridge

US101 (hwy 9) over Slide Viaduct is a prestressed concrete box beam or girders - multiple carrying US101 (hwy 9) over Slide Viaduct in Lane County, Oregon. It was built in 1962, so it is 63 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 3,187 vehicles a day, roughly 8% of them trucks, projected to reach 4,500 by 2042. The structure is 143 ft (43.6 m) long and 35 ft wide. If it were closed, the detour would be 81.4 mi (131 km).

Location

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CarriesUS101 (hwy 9)
CrossesSlide Viaduct
Location11.5 MI N HWY 062 JCT
RouteU.S. Route 101
CountyLane County
StateOregon
Coordinates44.1277, -124.1232
Functional classRural Principal Arterial - Other

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations on dry land well above flood water elevations
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating43.5 US tons
Inventory rating33.6 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans2
Design loadH 20
Structure length143 ft (43.6 m)
Longest span95 ft (29 m)
Deck width35 ft (10.7 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,187 (2022)
Projected traffic4,500 by 2042
Trucks8%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesRelief for waterway
Detour if closed81.4 mi (131 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkNon-Interstate 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 US101 (hwy 9) over Slide Viaduct built?

It was built in 1962, making it 63 years old in 2025.

What condition is US101 (hwy 9) over Slide Viaduct 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 US101 (hwy 9) over Slide Viaduct carry?

About 3,187 vehicles per day (2022 count), of which roughly 8% are trucks.

How long is US101 (hwy 9) over Slide Viaduct?

The structure is 143 ft (43.6 m) long with a longest span of 95 ft (29 m) and a deck 35 ft wide.

Who owns US101 (hwy 9) over Slide Viaduct?

It is owned by the State Highway Agency.