US Bridges

LA0506 over Little Black Bayou

Good

Caldwell Parish, Louisiana · 0.03 M E of US 165 · Structure no. 581103450400031

Built
2004
21 years old
Condition
Good
inspected July 2024
Type
Slab
Concrete
Length
98 ft
5 main spans
Daily traffic
411
2021 count
Owner
State
State Highway Agency

About this bridge

LA0506 over Little Black Bayou is a concrete slab carrying LA0506 over Little Black Bayou in Caldwell Parish, Louisiana. It was built in 2004, so it is 21 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 411 vehicles a day, roughly 11% of them trucks, projected to reach 452 by 2041. The structure is 98 ft (29.9 m) long and 32 ft wide. If it were closed, the detour would be 13 mi (21 km).

CarriesLA0506
CrossesLittle Black Bayou
Location0.03 M E of US 165
RouteState Highway 506
Coordinates31.97811, -92.161
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.
Substructure8 Very GoodNo problems noted.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJuly 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating52.1 US tons
Inventory rating40.3 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans5
Design loadHS 20
Structure length98 ft (29.9 m)
Longest span19 ft (5.8 m)
Deck width32 ft (9.7 m)
Roadway width29 ft (8.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic411 (2021)
Projected traffic452 by 2041
Trucks11%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed13 mi (21 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 LA0506 over Little Black Bayou built?

It was built in 2004, making it 21 years old in 2025.

What condition is LA0506 over Little Black Bayou 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 July 2024.

How much traffic does LA0506 over Little Black Bayou carry?

About 411 vehicles per day (2021 count), of which roughly 11% are trucks.

How long is LA0506 over Little Black Bayou?

The structure is 98 ft (29.9 m) long with a longest span of 19 ft (5.8 m) and a deck 32 ft wide.

Who owns LA0506 over Little Black Bayou?

It is owned by the State Highway Agency.