US Bridges

Or 99W (hwy 91) over Flat Creek

FairPosted for load

Lane County, Oregon · 030 MI S Benton Lane CO L · Structure no. 01805B01W 10730

Built
1933
92 years old, rebuilt 1964
Condition
Fair
inspected April 2023
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
95 ft
5 main spans
Daily traffic
8,459
2022 count
Owner
State
State Highway Agency

About this bridge

Or 99W (hwy 91) over Flat Creek is a wood or timber stringer/multi-beam or girder carrying Or 99W (hwy 91) over Flat Creek in Lane County, Oregon. It was built in 1933 and reconstructed in 1964, so it is 92 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. Its operating status is: posted for other load-capacity restriction.

It carries about 8,459 vehicles a day, roughly 17% of them trucks, projected to reach 10,800 by 2042. The structure is 95 ft (29 m) long and 46 ft wide. If it were closed, the detour would be 2.5 mi (4 km).

Location

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CarriesOr 99W (hwy 91)
CrossesFlat Creek
Location030 MI S Benton Lane CO L
RouteState Highway 99
CountyLane County
StateOregon
Coordinates44.24775, -123.22034
Functional classRural Minor Arterial

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 protection7 GoodSome minor problems.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusPosted for other load-capacity restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating23.9 US tons
Inventory rating18.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckConcrete, cast-in-place
Main spans5
Design loadH 15
Structure length95 ft (29 m)
Longest span19 ft (5.8 m)
Deck width46 ft (13.9 m)
Roadway width41 ft (12.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic8,459 (2022)
Projected traffic10,800 by 2042
Trucks17%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed2.5 mi (4 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 99W (hwy 91) over Flat Creek built?

It was built in 1933, making it 92 years old in 2025. It was reconstructed in 1964.

What condition is Or 99W (hwy 91) over Flat 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 April 2023.

How much traffic does Or 99W (hwy 91) over Flat Creek carry?

About 8,459 vehicles per day (2022 count), of which roughly 17% are trucks.

How long is Or 99W (hwy 91) over Flat Creek?

The structure is 95 ft (29 m) long with a longest span of 19 ft (5.8 m) and a deck 46 ft wide.

Who owns Or 99W (hwy 91) over Flat Creek?

It is owned by the State Highway Agency.