US Bridges

N3520 over Spring Creek

Fair

Pawnee County, Oklahoma · 4.E 1.5N of SH18/SH15 · Structure no. 103580000000000

Built
1946
79 years old
Condition
Fair
inspected August 2023
Type
Culvert
Concrete
Length
21 ft
2 main spans
Daily traffic
128
2022 count
Owner
County
County Highway Agency

About this bridge

N3520 over Spring Creek is a concrete culvert carrying N3520 over Spring Creek in Pawnee County, Oklahoma. It was built in 1946, so it is 79 years old, older than the Oklahoma average of 47.8 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 128 vehicles a day, roughly 15% of them trucks, projected to reach 205 by 2042. The structure is 21 ft (6.4 m) long and 24 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesN3520
CrossesSpring Creek
Location4.E 1.5N of SH18/SH15
RouteCounty Highway N3520
CountyPawnee County
StateOklahoma
Coordinates36.42754, -96.7285
Functional classRural Major 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
Channel and channel protection4 PoorAdvanced section loss, deterioration, spalling or scour.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; action required to protect exposed foundations
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating43.9 US tons
Inventory rating26.3 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20
Structure length21 ft (6.4 m)
Longest span10 ft (3 m)
Deck width24 ft (7.3 m)
Roadway width22 ft (6.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic128 (2022)
Projected traffic205 by 2042
Trucks15%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$225,000
NavigationNo navigation control on waterway

Frequently asked questions

When was N3520 over Spring Creek built?

It was built in 1946, making it 79 years old in 2025.

What condition is N3520 over Spring 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 August 2023.

How much traffic does N3520 over Spring Creek carry?

About 128 vehicles per day (2022 count), of which roughly 15% are trucks.

How long is N3520 over Spring Creek?

The structure is 21 ft (6.4 m) long with a longest span of 10 ft (3 m) and a deck 24 ft wide.

Who owns N3520 over Spring Creek?

It is owned by the County Highway Agency.