US Bridges

Nelson Mountain RD over Lake Creek

Fair

Lane County, Oregon · 060 MI SW of Triangle Lk · Structure no. 39C386367000008

Built
1928
97 years old, rebuilt 1984
Condition
Fair
inspected September 2023
Type
Slab
Prestressed Concrete
Length
156 ft
4 main spans
Daily traffic
273
2020 count
Owner
County
County Highway Agency

About this bridge

Nelson Mountain RD over Lake Creek is a prestressed concrete slab carrying Nelson Mountain RD over Lake Creek in Lane County, Oregon. It was built in 1928 and reconstructed in 1984, so it is 97 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 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 273 vehicles a day, roughly 20% of them trucks, projected to reach 318 by 2025. The structure is 156 ft (47.5 m) long and 16 ft wide. If it were closed, the detour would be 18.6 mi (30 km).

Location

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CarriesNelson Mountain RD
CrossesLake Creek
Location060 MI SW of Triangle Lk
RouteCounty Highway C0367
CountyLane County
StateOregon
Coordinates44.10434, -123.67363
Functional classRural Minor Collector

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.
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 inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating48 US tons
Inventory rating29 US tons

Structure

Structure typeSlab
MaterialPrestressed Concrete
DeckWood or timber
Main spans4
Design loadHS 20
Structure length156 ft (47.5 m)
Longest span52 ft (15.8 m)
Deck width16 ft (4.9 m)
Roadway width14 ft (4.2 m)
Vertical clearance over deck14 ft (4.3 m)

Traffic and service

Average daily traffic273 (2020)
Projected traffic318 by 2025
Trucks20%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed18.6 mi (30 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusListed on the National Register of Historic Places
Work proposedWidening of existing bridge without deck rehabilitation
Estimated improvement cost$799,000
NavigationNo navigation control on waterway

Frequently asked questions

When was Nelson Mountain RD over Lake Creek built?

It was built in 1928, making it 97 years old in 2025. It was reconstructed in 1984.

What condition is Nelson Mountain RD over Lake 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 September 2023.

How much traffic does Nelson Mountain RD over Lake Creek carry?

About 273 vehicles per day (2020 count), of which roughly 20% are trucks.

How long is Nelson Mountain RD over Lake Creek?

The structure is 156 ft (47.5 m) long with a longest span of 52 ft (15.8 m) and a deck 16 ft wide.

Who owns Nelson Mountain RD over Lake Creek?

It is owned by the County Highway Agency.