US Bridges

N4520 over Fly Creek

Fair

Delaware County, Oklahoma · 2 NW of Bernice · Structure no. 303760000000000

Built
2017
8 years old
Condition
Fair
inspected February 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
93 ft
1 main span
Daily traffic
100
2022 count
Owner
County
County Highway Agency

About this bridge

N4520 over Fly Creek is a prestressed concrete stringer/multi-beam or girder carrying N4520 over Fly Creek in Delaware County, Oklahoma. It was built in 2017, so it is 8 years old, younger 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 100 vehicles a day, roughly 10% of them trucks, projected to reach 160 by 2042. The structure is 93 ft (28.3 m) long and 34 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesN4520
CrossesFly Creek
Location2 NW of Bernice
RouteCounty Highway N4520
CountyDelaware County
StateOklahoma
Coordinates36.63691, -94.94605
Functional classRural Local

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure8 Very GoodNo problems noted.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionFebruary 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry8: Equal to present desirable criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating80 US tons
Inventory rating48 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length93 ft (28.3 m)
Longest span90 ft (27.4 m)
Deck width34 ft (10.5 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deck100 ft (30.5 m)

Traffic and service

Average daily traffic100 (2022)
Projected traffic160 by 2042
Trucks10%
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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was N4520 over Fly Creek built?

It was built in 2017, making it 8 years old in 2025.

What condition is N4520 over Fly 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 February 2023.

How much traffic does N4520 over Fly Creek carry?

About 100 vehicles per day (2022 count), of which roughly 10% are trucks.

How long is N4520 over Fly Creek?

The structure is 93 ft (28.3 m) long with a longest span of 90 ft (27.4 m) and a deck 34 ft wide.

Who owns N4520 over Fly Creek?

It is owned by the County Highway Agency.