US Bridges

LA0621 over Black Bayou Canal

Fair

Ascension Parish, Louisiana · 0.6 M E of US 61 · Structure no. 610308030803131

Built
1967
58 years old
Condition
Fair
inspected October 2024
Type
Slab
Concrete
Length
59 ft
3 main spans
Daily traffic
7,519
2021 count
Owner
State
State Highway Agency

About this bridge

LA0621 over Black Bayou Canal is a concrete slab carrying LA0621 over Black Bayou Canal in Ascension Parish, Louisiana. It was built in 1967, so it is 58 years old, older 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 5 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 7,519 vehicles a day, roughly 7% of them trucks, projected to reach 8,270 by 2041. The structure is 59 ft (18 m) long and 29 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesLA0621
CrossesBlack Bayou Canal
Location0.6 M E of US 61
RouteState Highway 621
CountyAscension Parish
StateLouisiana
Coordinates30.26945, -90.93239
Functional classUrban Minor Arterial

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating27.4 US tons
Inventory rating21.1 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, precast panels
Main spans3
Design loadHS 20
Structure length59 ft (18 m)
Longest span19 ft (5.8 m)
Deck width29 ft (8.7 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic7,519 (2021)
Projected traffic8,270 by 2041
Trucks7%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$319,000
NavigationNo navigation control on waterway

Frequently asked questions

When was LA0621 over Black Bayou Canal built?

It was built in 1967, making it 58 years old in 2025.

What condition is LA0621 over Black Bayou Canal 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 October 2024.

How much traffic does LA0621 over Black Bayou Canal carry?

About 7,519 vehicles per day (2021 count), of which roughly 7% are trucks.

How long is LA0621 over Black Bayou Canal?

The structure is 59 ft (18 m) long with a longest span of 19 ft (5.8 m) and a deck 29 ft wide.

Who owns LA0621 over Black Bayou Canal?

It is owned by the State Highway Agency.