US Bridges

LA3105 over Coopers Bayou

Fair

Bossier Parish, Louisiana · 0.1 MI North of LA 72 · Structure no. 040808080702231

Built
1975
50 years old, rebuilt 1984
Condition
Fair
inspected November 2024
Type
Slab
Concrete
Length
60 ft
3 main spans
Daily traffic
32,603
2021 count
Owner
State
State Highway Agency

About this bridge

LA3105 over Coopers Bayou is a concrete slab carrying LA3105 over Coopers Bayou in Bossier Parish, Louisiana. It was built in 1975 and reconstructed in 1984, so it is 50 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 32,603 vehicles a day, roughly 8% of them trucks, projected to reach 35,863 by 2041. The structure is 60 ft (18.3 m) long and 86 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesLA3105
CrossesCoopers Bayou
Location0.1 MI North of LA 72
RouteState Highway 3105
CountyBossier Parish
StateLouisiana
Coordinates32.5224, -93.6971
Functional classUrban Other Principal 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 protection8 Very GoodNo problems noted.
Last inspectionNovember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry9: Superior to present desirable criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating79 US tons
Inventory rating47 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length60 ft (18.3 m)
Longest span20 ft (6.1 m)
Deck width86 ft (26.3 m)
Roadway width68 ft (20.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic32,603 (2021)
Projected traffic35,863 by 2041
Trucks8%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes

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 LA3105 over Coopers Bayou built?

It was built in 1975, making it 50 years old in 2025. It was reconstructed in 1984.

What condition is LA3105 over Coopers 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 November 2024.

How much traffic does LA3105 over Coopers Bayou carry?

About 32,603 vehicles per day (2021 count), of which roughly 8% are trucks.

How long is LA3105 over Coopers Bayou?

The structure is 60 ft (18.3 m) long with a longest span of 20 ft (6.1 m) and a deck 86 ft wide.

Who owns LA3105 over Coopers Bayou?

It is owned by the State Highway Agency.