US Bridges

LA0004 over Black Lake Bayou

Fair

Bienville Parish, Louisiana · 6.3 MI East of LA 154 · Structure no. 040700670207021

Built
1982
43 years old
Condition
Fair
inspected May 2023
Type
Slab
Concrete
Length
280 ft
14 main spans
Daily traffic
1,087
2021 count
Owner
State
State Highway Agency

About this bridge

LA0004 over Black Lake Bayou is a concrete slab carrying LA0004 over Black Lake Bayou in Bienville Parish, Louisiana. It was built in 1982, so it is 43 years old, younger than the Louisiana average of 43 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 1,087 vehicles a day, roughly 19% of them trucks, projected to reach 1,195 by 2041. The structure is 280 ft (85.3 m) long and 33 ft wide. If it were closed, the detour would be 11.2 mi (18 km).

CarriesLA0004
CrossesBlack Lake Bayou
Location6.3 MI East of LA 154
RouteState Highway 4
Coordinates32.26078, -93.2145
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating75 US tons
Inventory rating45 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans14
Design loadHS 20
Structure length280 ft (85.3 m)
Longest span20 ft (6.1 m)
Deck width33 ft (10 m)
Roadway width30 ft (9.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,087 (2021)
Projected traffic1,195 by 2041
Trucks19%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed11.2 mi (18 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 LA0004 over Black Lake Bayou built?

It was built in 1982, making it 43 years old in 2025.

What condition is LA0004 over Black Lake Bayou 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 May 2023.

How much traffic does LA0004 over Black Lake Bayou carry?

About 1,087 vehicles per day (2021 count), of which roughly 19% are trucks.

How long is LA0004 over Black Lake Bayou?

The structure is 280 ft (85.3 m) long with a longest span of 20 ft (6.1 m) and a deck 33 ft wide.

Who owns LA0004 over Black Lake Bayou?

It is owned by the State Highway Agency.