US Bridges

LA0399 over Flat Branch

FairPosted for load

Vernon Parish, Louisiana · 1.99 MI North of LA 10 · Structure no. 085801380301991

Built
1964
61 years old
Condition
Fair
inspected March 2024
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
39 ft
2 main spans
Daily traffic
396
2021 count
Owner
State
State Highway Agency

About this bridge

LA0399 over Flat Branch is a wood or timber stringer/multi-beam or girder carrying LA0399 over Flat Branch in Vernon Parish, Louisiana. It was built in 1964, so it is 61 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. Its operating status is: posted for load restriction.

It carries about 396 vehicles a day, roughly 10% of them trucks, projected to reach 435 by 2041. The structure is 39 ft (11.9 m) long and 26 ft wide. If it were closed, the detour would be 11.8 mi (19 km).

Location

Open in Google Maps
CarriesLA0399
CrossesFlat Branch
Location1.99 MI North of LA 10
RouteState Highway 399
CountyVernon Parish
StateLouisiana
Coordinates30.98587, -92.9975
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
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 inspectionMarch 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
Structural evaluation2: Basically intolerable, requiring high priority of replacement
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating7.1 US tons
Inventory rating1 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans2
Design loadH 15
Structure length39 ft (11.9 m)
Longest span19 ft (5.8 m)
Deck width26 ft (7.9 m)
Roadway width23 ft (6.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic396 (2021)
Projected traffic435 by 2041
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed11.8 mi (19 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$234,000
NavigationNo navigation control on waterway

Frequently asked questions

When was LA0399 over Flat Branch built?

It was built in 1964, making it 61 years old in 2025.

What condition is LA0399 over Flat Branch 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 March 2024.

How much traffic does LA0399 over Flat Branch carry?

About 396 vehicles per day (2021 count), of which roughly 10% are trucks.

How long is LA0399 over Flat Branch?

The structure is 39 ft (11.9 m) long with a longest span of 19 ft (5.8 m) and a deck 26 ft wide.

Who owns LA0399 over Flat Branch?

It is owned by the State Highway Agency.