US Bridges

East Mapleton Road over Knowles Creek

Fair

Lane County, Oregon · 005MI E JCT HWY36 & US126 · Structure no. 39C516503000002

Built
1966
59 years old
Condition
Fair
inspected September 2023
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
145 ft
1 main span
Daily traffic
2,444
2020 count
Owner
County
County Highway Agency

About this bridge

East Mapleton Road over Knowles Creek is a prestressed concrete box beam or girders - multiple carrying East Mapleton Road over Knowles Creek in Lane County, Oregon. It was built in 1966, so it is 59 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 2,444 vehicles a day, roughly 10% of them trucks, projected to reach 2,864 by 2025. The structure is 145 ft (44.2 m) long and 36 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesEast Mapleton Road
CrossesKnowles Creek
Location005MI E JCT HWY36 & US126
RouteCounty Highway C5030
CountyLane County
StateOregon
Coordinates44.03335, -123.85501
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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating20.7 US tons
Inventory rating16.1 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete
DeckOther
Main spans1 (+3 approach)
Design loadHS 20
Structure length145 ft (44.2 m)
Longest span60 ft (18.3 m)
Deck width36 ft (11 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,444 (2020)
Projected traffic2,864 by 2025
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was East Mapleton Road over Knowles Creek built?

It was built in 1966, making it 59 years old in 2025.

What condition is East Mapleton Road over Knowles 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 East Mapleton Road over Knowles Creek carry?

About 2,444 vehicles per day (2020 count), of which roughly 10% are trucks.

How long is East Mapleton Road over Knowles Creek?

The structure is 145 ft (44.2 m) long with a longest span of 60 ft (18.3 m) and a deck 36 ft wide.

Who owns East Mapleton Road over Knowles Creek?

It is owned by the County Highway Agency.