US Bridges

Combon Bridge RD over Grand Caillou Bayou

FairPosted for load

Terrebonne Parish, Louisiana · 0.08 MI West of LA 57 · Structure no. 025529255904241

Built
1990
35 years old
Condition
Fair
inspected June 2023
Type
Movable - Lift
Steel
Length
256 ft
1 main span
Daily traffic
1,566
2023 count
Owner
County
County Highway Agency

About this bridge

Combon Bridge RD over Grand Caillou Bayou is a steel movable - lift carrying Combon Bridge RD over Grand Caillou Bayou in Terrebonne Parish, Louisiana. It was built in 1990, so it is 35 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. Its operating status is: posted for load restriction.

It carries about 1,566 vehicles a day, projected to reach 1,722 by 2043. The structure is 256 ft (78 m) long and 34 ft wide. If it were closed, the detour would be 6.8 mi (11 km).

Location

Open in Google Maps
CarriesCombon Bridge RD
CrossesGrand Caillou Bayou
Location0.08 MI West of LA 57
RouteCounty Highway 0
CountyTerrebonne Parish
StateLouisiana
Coordinates29.43023, -90.70056
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
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 alignment8: Equal to present desirable criteria
Operating rating45.7 US tons
Inventory rating35.4 US tons

Structure

Structure typeMovable - Lift
MaterialSteel
DeckOpen grating
Main spans1 (+9 approach)
Design loadHS 20
Structure length256 ft (78 m)
Longest span76 ft (23.2 m)
Deck width34 ft (10.4 m)
Roadway width28 ft (8.6 m)
Vertical clearance over deck17 ft (5.1 m)

Traffic and service

Average daily traffic1,566 (2023)
Projected traffic1,722 by 2043
Trucks—
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed6.8 mi (11 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNavigation control on waterway (bridge permit required)

Frequently asked questions

When was Combon Bridge RD over Grand Caillou Bayou built?

It was built in 1990, making it 35 years old in 2025.

What condition is Combon Bridge RD over Grand Caillou 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 June 2023.

How much traffic does Combon Bridge RD over Grand Caillou Bayou carry?

About 1,566 vehicles per day (2023 count).

How long is Combon Bridge RD over Grand Caillou Bayou?

The structure is 256 ft (78 m) long with a longest span of 76 ft (23.2 m) and a deck 34 ft wide.

Who owns Combon Bridge RD over Grand Caillou Bayou?

It is owned by the County Highway Agency.