US Bridges

LA0491 over Bayou Nid Aigle

Good

Natchitoches Parish, Louisiana · 5.3 Mi. North of LA 495 · Structure no. 083500000080544

Built
2010
15 years old
Condition
Good
inspected April 2024
Type
Slab
Concrete
Length
160 ft
8 main spans
Daily traffic
237
2021 count
Owner
State
State Highway Agency

About this bridge

LA0491 over Bayou Nid Aigle is a concrete slab carrying LA0491 over Bayou Nid Aigle in Natchitoches Parish, Louisiana. It was built in 2010, so it is 15 years old, younger than the Louisiana average of 43 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 237 vehicles a day, roughly 10% of them trucks, projected to reach 260 by 2041. The structure is 160 ft (48.8 m) long and 32 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

CarriesLA0491
CrossesBayou Nid Aigle
Location5.3 Mi. North of LA 495
RouteState Highway 491
Coordinates31.58117, -92.8566
Functional classRural Local

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating52.9 US tons
Inventory rating40.7 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans8
Design loadHL 93
Structure length160 ft (48.8 m)
Longest span20 ft (6.1 m)
Deck width32 ft (9.8 m)
Roadway width29 ft (8.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic237 (2021)
Projected traffic260 by 2041
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed98.8 mi (159 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState 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 LA0491 over Bayou Nid Aigle built?

It was built in 2010, making it 15 years old in 2025.

What condition is LA0491 over Bayou Nid Aigle in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in April 2024.

How much traffic does LA0491 over Bayou Nid Aigle carry?

About 237 vehicles per day (2021 count), of which roughly 10% are trucks.

How long is LA0491 over Bayou Nid Aigle?

The structure is 160 ft (48.8 m) long with a longest span of 20 ft (6.1 m) and a deck 32 ft wide.

Who owns LA0491 over Bayou Nid Aigle?

It is owned by the State Highway Agency.