US Bridges

LA0642 over Marvin Canal

Fair

St. James Parish, Louisiana · 0.6 M W of LA 3125 · Structure no. 614708470101101

Built
1979
46 years old
Condition
Fair
inspected February 2023
Type
Slab
Concrete
Length
57 ft
3 main spans
Daily traffic
410
2021 count
Owner
State
State Highway Agency

About this bridge

LA0642 over Marvin Canal is a concrete slab carrying LA0642 over Marvin Canal in St. James Parish, Louisiana. It was built in 1979, so it is 46 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 410 vehicles a day, roughly 19% of them trucks, projected to reach 451 by 2041. The structure is 57 ft (17.4 m) long and 31 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

Location

Open in Google Maps
CarriesLA0642
CrossesMarvin Canal
Location0.6 M W of LA 3125
RouteState Highway 642
CountySt. James Parish
StateLouisiana
Coordinates30.04484, -90.7518
Functional classUrban 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.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionFebruary 2023
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 geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating41.1 US tons
Inventory rating31.7 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, precast panels
Main spans3
Design loadHS 20
Structure length57 ft (17.4 m)
Longest span19 ft (5.8 m)
Deck width31 ft (9.4 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic410 (2021)
Projected traffic451 by 2041
Trucks19%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed98.8 mi (159 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 LA0642 over Marvin Canal built?

It was built in 1979, making it 46 years old in 2025.

What condition is LA0642 over Marvin Canal 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 February 2023.

How much traffic does LA0642 over Marvin Canal carry?

About 410 vehicles per day (2021 count), of which roughly 19% are trucks.

How long is LA0642 over Marvin Canal?

The structure is 57 ft (17.4 m) long with a longest span of 19 ft (5.8 m) and a deck 31 ft wide.

Who owns LA0642 over Marvin Canal?

It is owned by the State Highway Agency.