US Bridges

LA0306 over Grand Bayou

Fair

St. Charles Parish, Louisiana · 2.0 MI South of LA 632 · Structure no. 024508450706651

Built
1984
41 years old
Condition
Fair
inspected April 2024
Type
Slab
Concrete
Length
160 ft
8 main spans
Daily traffic
370
2016 count
Owner
State
State Highway Agency

About this bridge

LA0306 over Grand Bayou is a concrete slab carrying LA0306 over Grand Bayou in St. Charles Parish, Louisiana. It was built in 1984, so it is 41 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 370 vehicles a day, roughly 13% of them trucks, projected to reach 407 by 2036. The structure is 160 ft (48.8 m) long and 33 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

Open in Google Maps
CarriesLA0306
CrossesGrand Bayou
Location2.0 MI South of LA 632
RouteState Highway 306
CountySt. Charles Parish
StateLouisiana
Coordinates29.79057, -90.4237
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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to 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 rating75 US tons
Inventory rating45 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans8
Design loadHS 20
Structure length160 ft (48.8 m)
Longest span20 ft (6.1 m)
Deck width33 ft (10.1 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic370 (2016)
Projected traffic407 by 2036
Trucks13%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 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 LA0306 over Grand Bayou built?

It was built in 1984, making it 41 years old in 2025.

What condition is LA0306 over Grand 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 April 2024.

How much traffic does LA0306 over Grand Bayou carry?

About 370 vehicles per day (2016 count), of which roughly 13% are trucks.

How long is LA0306 over Grand Bayou?

The structure is 160 ft (48.8 m) long with a longest span of 20 ft (6.1 m) and a deck 33 ft wide.

Who owns LA0306 over Grand Bayou?

It is owned by the State Highway Agency.