US Bridges

S. Thonpson RD over Lateral 4B

Fair

Calcasieu Parish, Louisiana · 1.8 MI South of US 90 · Structure no. 071030132930071

Built
2002
23 years old
Condition
Fair
inspected May 2023
Type
Slab
Concrete
Length
57 ft
3 main spans
Daily traffic
692
2022 count
Owner
County
County Highway Agency

About this bridge

S. Thonpson RD over Lateral 4B is a concrete slab carrying S. Thonpson RD over Lateral 4B in Calcasieu Parish, Louisiana. It was built in 2002, so it is 23 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.

It carries about 692 vehicles a day, projected to reach 761 by 2042. The structure is 57 ft (17.4 m) long and 31 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesS. Thonpson RD
CrossesLateral 4B
Location1.8 MI South of US 90
RouteCounty Highway 0
CountyCalcasieu Parish
StateLouisiana
Coordinates30.20575, -93.01329
Functional classRural Minor Arterial

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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionMay 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 alignment8: Equal to present desirable criteria
Operating rating27.9 US tons
Inventory rating21.8 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
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 traffic692 (2022)
Projected traffic761 by 2042
Trucks—
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was S. Thonpson RD over Lateral 4B built?

It was built in 2002, making it 23 years old in 2025.

What condition is S. Thonpson RD over Lateral 4B 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 May 2023.

How much traffic does S. Thonpson RD over Lateral 4B carry?

About 692 vehicles per day (2022 count).

How long is S. Thonpson RD over Lateral 4B?

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 S. Thonpson RD over Lateral 4B?

It is owned by the County Highway Agency.