US Bridges

LA0485 over Middle Bayou

Good

Natchitoches Parish, Louisiana · 1.96 M E of I-49 · Structure no. 083500000083506

Built
2023
2 years old
Condition
Good
inspected October 2023
Type
Culvert
Concrete
Length
41 ft
4 main spans
Daily traffic
700
2021 count
Owner
State
State Highway Agency

About this bridge

LA0485 over Middle Bayou is a concrete culvert carrying LA0485 over Middle Bayou in Natchitoches Parish, Louisiana. It was built in 2023, so it is 2 years old, younger than the Louisiana average of 43 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 9 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 700 vehicles a day, roughly 12% of them trucks, projected to reach 770 by 2041. The structure is 41 ft (12.5 m) long and 86 ft wide. If it were closed, the detour would be 11.8 mi (19 km).

CarriesLA0485
CrossesMiddle Bayou
Location1.96 M E of I-49
RouteState Highway 485
Coordinates31.83888, -93.24555
Functional classRural Minor Collector

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Channel and channel protection9 ExcellentNo problems noted.
Culvert9 ExcellentNo problems noted.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation9: Superior to present desirable criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating52.1 US tons
Inventory rating40.3 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckNot applicable
Main spans4
Design loadGreater than HL 93
Structure length41 ft (12.5 m)
Longest span8 ft (2.4 m)
Deck width86 ft (26.1 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic700 (2021)
Projected traffic770 by 2041
Trucks12%
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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was LA0485 over Middle Bayou built?

It was built in 2023, making it 2 years old in 2025.

What condition is LA0485 over Middle Bayou in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in October 2023.

How much traffic does LA0485 over Middle Bayou carry?

About 700 vehicles per day (2021 count), of which roughly 12% are trucks.

How long is LA0485 over Middle Bayou?

The structure is 41 ft (12.5 m) long with a longest span of 8 ft (2.4 m) and a deck 86 ft wide.

Who owns LA0485 over Middle Bayou?

It is owned by the State Highway Agency.