US Bridges

Siegman Smyth Road over Nail Creek

Fair

Lane County, Oregon · 020 MI West of Cheshire · Structure no. 39C334345800143

Built
1979
46 years old
Condition
Fair
inspected October 2024
Type
Slab
Prestressed Concrete
Length
28 ft
1 main span
Daily traffic
225
2020 count
Owner
County
County Highway Agency

About this bridge

Siegman Smyth Road over Nail Creek is a prestressed concrete slab carrying Siegman Smyth Road over Nail Creek in Lane County, Oregon. It was built in 1979, so it is 46 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 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 225 vehicles a day, projected to reach 240 by 2025. The structure is 28 ft (8.5 m) long and 28 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

Open in Google Maps
CarriesSiegman Smyth Road
CrossesNail Creek
Location020 MI West of Cheshire
RouteCounty Highway C3458
CountyLane County
StateOregon
Coordinates44.20115, -123.33256
Functional classRural 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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating73 US tons
Inventory rating44 US tons

Structure

Structure typeSlab
MaterialPrestressed Concrete
DeckOther
Main spans1
Design loadHS 20
Structure length28 ft (8.5 m)
Longest span27 ft (8.2 m)
Deck width28 ft (8.5 m)
Roadway width27 ft (8.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic225 (2020)
Projected traffic240 by 2025
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty 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 Siegman Smyth Road over Nail Creek built?

It was built in 1979, making it 46 years old in 2025.

What condition is Siegman Smyth Road over Nail Creek 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 October 2024.

How much traffic does Siegman Smyth Road over Nail Creek carry?

About 225 vehicles per day (2020 count).

How long is Siegman Smyth Road over Nail Creek?

The structure is 28 ft (8.5 m) long with a longest span of 27 ft (8.2 m) and a deck 28 ft wide.

Who owns Siegman Smyth Road over Nail Creek?

It is owned by the County Highway Agency.