US Bridges

Or 78 (hwy 442) over Silvies SLOUGH(14th Br)

Good

Harney County, Oregon · 3.2 Mi. E. Jct. US 20/395 · Structure no. 03592A442 00323

Built
1971
54 years old
Condition
Good
inspected October 2024
Type
Slab
Prestressed Concrete
Length
35 ft
1 main span
Daily traffic
1,299
2022 count
Owner
State
State Highway Agency

About this bridge

Or 78 (hwy 442) over Silvies SLOUGH(14th Br) is a prestressed concrete slab carrying Or 78 (hwy 442) over Silvies SLOUGH(14th Br) in Harney 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 good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 1,299 vehicles a day, roughly 33% of them trucks, projected to reach 1,700 by 2042. The structure is 35 ft (10.7 m) long and 36 ft wide. If it were closed, the detour would be 28 mi (45 km).

CarriesOr 78 (hwy 442)
CrossesSilvies SLOUGH(14th Br)
Location3.2 Mi. E. Jct. US 20/395
RouteState Highway 78
StateOregon
Coordinates43.58573, -118.99007
Functional classRural Minor Arterial

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure8 Very GoodNo problems noted.
Channel and channel protection7 GoodSome minor problems.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation7: Better than present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating51.8 US tons
Inventory rating40 US tons

Structure

Structure typeSlab
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans1
Design loadHS 20
Structure length35 ft (10.7 m)
Longest span34 ft (10.4 m)
Deck width36 ft (11 m)
Roadway width34 ft (10.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,299 (2022)
Projected traffic1,700 by 2042
Trucks33%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed28 mi (45 km)
TollOn a free road
National Highway SystemNo

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—
NavigationNo navigation control on waterway

Frequently asked questions

When was Or 78 (hwy 442) over Silvies SLOUGH(14th Br) built?

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

What condition is Or 78 (hwy 442) over Silvies SLOUGH(14th Br) in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in October 2024.

How much traffic does Or 78 (hwy 442) over Silvies SLOUGH(14th Br) carry?

About 1,299 vehicles per day (2022 count), of which roughly 33% are trucks.

How long is Or 78 (hwy 442) over Silvies SLOUGH(14th Br)?

The structure is 35 ft (10.7 m) long with a longest span of 34 ft (10.4 m) and a deck 36 ft wide.

Who owns Or 78 (hwy 442) over Silvies SLOUGH(14th Br)?

It is owned by the State Highway Agency.