US Bridges

Or 78 (hwy 442) over Silvies Slough (1st Br)

Good

Harney County, Oregon · 0.7 Mi. E. Jct. US 20/395 · Structure no. 20868 442 00069

Built
2010
15 years old
Condition
Good
inspected October 2024
Type
Slab
Prestressed Concrete
Length
39 ft
1 main span
Daily traffic
1,858
2022 count
Owner
State
State Highway Agency

About this bridge

Or 78 (hwy 442) over Silvies Slough (1st Br) is a prestressed concrete slab carrying Or 78 (hwy 442) over Silvies Slough (1st Br) in Harney County, Oregon. It was built in 2010, so it is 15 years old, younger 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 8 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 1,858 vehicles a day, roughly 37% of them trucks, projected to reach 2,000 by 2042. The structure is 39 ft (12 m) long and 40 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesOr 78 (hwy 442)
CrossesSilvies Slough (1st Br)
Location0.7 Mi. E. Jct. US 20/395
RouteState Highway 78
CountyHarney County
StateOregon
Coordinates43.58563, -119.04071
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
Deck8 Very GoodNo problems noted.
Superstructure8 Very GoodNo problems noted.
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 evaluation8: Equal to present desirable criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating63.6 US tons
Inventory rating48.9 US tons

Structure

Structure typeSlab
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans1
Design loadHL 93
Structure length39 ft (12 m)
Longest span38 ft (11.7 m)
Deck width40 ft (12.2 m)
Roadway width36 ft (11 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,858 (2022)
Projected traffic2,000 by 2042
Trucks37%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 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 (1st Br) built?

It was built in 2010, making it 15 years old in 2025.

What condition is Or 78 (hwy 442) over Silvies Slough (1st 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 (1st Br) carry?

About 1,858 vehicles per day (2022 count), of which roughly 37% are trucks.

How long is Or 78 (hwy 442) over Silvies Slough (1st Br)?

The structure is 39 ft (12 m) long with a longest span of 38 ft (11.7 m) and a deck 40 ft wide.

Who owns Or 78 (hwy 442) over Silvies Slough (1st Br)?

It is owned by the State Highway Agency.