US Bridges

Upper N Fork Road over Porter Creek

Fair

Lane County, Oregon · 170 MI NE of Florence · Structure no. 39C578508400490

Built
1975
50 years old
Condition
Fair
inspected September 2023
Type
Tee Beam
Concrete Continuous
Length
65 ft
1 main span
Daily traffic
163
2020 count
Owner
County
County Highway Agency

About this bridge

Upper N Fork Road over Porter Creek is a concrete continuous tee beam carrying Upper N Fork Road over Porter Creek in Lane County, Oregon. It was built in 1975, so it is 50 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 163 vehicles a day, roughly 5% of them trucks, projected to reach 193 by 2025. The structure is 65 ft (19.8 m) long and 17 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesUpper N Fork Road
CrossesPorter Creek
Location170 MI NE of Florence
RouteCounty Highway C5084
CountyLane County
StateOregon
Coordinates44.11397, -123.93556
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.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating59 US tons
Inventory rating35.1 US tons

Structure

Structure typeTee Beam
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length65 ft (19.8 m)
Longest span40 ft (12.2 m)
Deck width17 ft (5.3 m)
Roadway width14 ft (4.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic163 (2020)
Projected traffic193 by 2025
Trucks5%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed123.7 mi (199 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedWidening of existing bridge without deck rehabilitation
Estimated improvement cost$333,000
NavigationNo navigation control on waterway

Frequently asked questions

When was Upper N Fork Road over Porter Creek built?

It was built in 1975, making it 50 years old in 2025.

What condition is Upper N Fork Road over Porter 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 Upper N Fork Road over Porter Creek carry?

About 163 vehicles per day (2020 count), of which roughly 5% are trucks.

How long is Upper N Fork Road over Porter Creek?

The structure is 65 ft (19.8 m) long with a longest span of 40 ft (12.2 m) and a deck 17 ft wide.

Who owns Upper N Fork Road over Porter Creek?

It is owned by the County Highway Agency.