US Bridges

US0090 over Mermentau River

Good

Acadia Parish, Louisiana · 1.5 Mi. West of LA 92 · Structure no. 030100030900001

Built
1980
45 years old
Condition
Good
inspected March 2024
Type
Girder and Floorbeam System
Steel Continuous
Length
2,031 ft
2 main spans
Daily traffic
2,899
2021 count
Owner
State
State Highway Agency

About this bridge

US0090 over Mermentau River is a steel continuous girder and floorbeam system carrying US0090 over Mermentau River in Acadia Parish, Louisiana. It was built in 1980, so it is 45 years old, older 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 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 2,899 vehicles a day, roughly 13% of them trucks, projected to reach 3,188 by 2041. The structure is 2,031 ft (619 m) long and 43 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesUS0090
CrossesMermentau River
Location1.5 Mi. West of LA 92
RouteU.S. Route 90
CountyAcadia Parish
StateLouisiana
Coordinates30.19098, -92.59382
Functional classRural Minor Arterial

Condition and inspection

Good

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

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionMarch 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation7: Better than present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating85 US tons
Inventory rating36 US tons

Structure

Structure typeGirder and Floorbeam System
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans2 (+29 approach)
Design loadHS 20
Structure length2,031 ft (619 m)
Longest span150 ft (45.7 m)
Deck width43 ft (13 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,899 (2021)
Projected traffic3,188 by 2041
Trucks13%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 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—
NavigationNavigation control on waterway (bridge permit required)

Frequently asked questions

When was US0090 over Mermentau River built?

It was built in 1980, making it 45 years old in 2025.

What condition is US0090 over Mermentau River 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 March 2024.

How much traffic does US0090 over Mermentau River carry?

About 2,899 vehicles per day (2021 count), of which roughly 13% are trucks.

How long is US0090 over Mermentau River?

The structure is 2,031 ft (619 m) long with a longest span of 150 ft (45.7 m) and a deck 43 ft wide.

Who owns US0090 over Mermentau River?

It is owned by the State Highway Agency.