US Bridges

I0049 over Bayou Derbonne

Poor

Natchitoches Parish, Louisiana · 0.69 Miles North of LA 11 · Structure no. 083504550611101

Built
1986
39 years old
Condition
Poor
inspected June 2024
Type
Culvert
Steel
Length
50 ft
4 main spans
Daily traffic
18,305
2021 count
Owner
State
State Highway Agency

About this bridge

I0049 over Bayou Derbonne is a steel culvert carrying I0049 over Bayou Derbonne in Natchitoches Parish, Louisiana. It was built in 1986, so it is 39 years old, younger than the Louisiana average of 43 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

It carries about 18,305 vehicles a day, roughly 30% of them trucks, projected to reach 20,135 by 2041. The structure is 50 ft (15.2 m) long and 358 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesI0049
CrossesBayou Derbonne
Location0.69 Miles North of LA 11
RouteInterstate 49
CountyNatchitoches Parish
StateLouisiana
Coordinates31.5359, -92.95523
Functional classRural Principal Arterial - Interstate

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Culvert4 PoorAdvanced section loss, deterioration, spalling or scour.
Last inspectionJune 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
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating107.1 US tons
Inventory rating82.1 US tons

Structure

Structure typeCulvert
MaterialSteel
DeckNot applicable
Main spans4
Design loadHS 20
Structure length50 ft (15.2 m)
Longest span10 ft (3 m)
Deck width358 ft (109.1 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic18,305 (2021)
Projected traffic20,135 by 2041
Trucks30%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

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$283,000
NavigationNo navigation control on waterway

Frequently asked questions

When was I0049 over Bayou Derbonne built?

It was built in 1986, making it 39 years old in 2025.

What condition is I0049 over Bayou Derbonne in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in June 2024.

How much traffic does I0049 over Bayou Derbonne carry?

About 18,305 vehicles per day (2021 count), of which roughly 30% are trucks.

How long is I0049 over Bayou Derbonne?

The structure is 50 ft (15.2 m) long with a longest span of 10 ft (3 m) and a deck 358 ft wide.

Who owns I0049 over Bayou Derbonne?

It is owned by the State Highway Agency.