US Bridges

US0171 over Diamond Gully

Fair

Calcasieu Parish, Louisiana · 3.6 MI N of LA 378-US171 · Structure no. 071000240204001

Built
1996
29 years old
Condition
Fair
inspected May 2023
Type
Slab
Concrete
Length
80 ft
4 main spans
Daily traffic
32,659
2021 count
Owner
State
State Highway Agency

About this bridge

US0171 over Diamond Gully is a concrete slab carrying US0171 over Diamond Gully in Calcasieu Parish, Louisiana. It was built in 1996, so it is 29 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 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 32,659 vehicles a day, roughly 17% of them trucks, projected to reach 35,924 by 2041. The structure is 80 ft (24.4 m) long and 43 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesUS0171
CrossesDiamond Gully
Location3.6 MI N of LA 378-US171
RouteU.S. Route 171
CountyCalcasieu Parish
StateLouisiana
Coordinates30.35448, -93.20023
Functional classUrban Other Principal 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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
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 geometry7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating41.8 US tons
Inventory rating32.2 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length80 ft (24.4 m)
Longest span20 ft (6.1 m)
Deck width43 ft (13 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic32,659 (2021)
Projected traffic35,924 by 2041
Trucks17%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkNon-Interstate STRAHNET route

Ownership and planned work

OwnerState Highway Agency
Maintained byState 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 US0171 over Diamond Gully built?

It was built in 1996, making it 29 years old in 2025.

What condition is US0171 over Diamond Gully 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 US0171 over Diamond Gully carry?

About 32,659 vehicles per day (2021 count), of which roughly 17% are trucks.

How long is US0171 over Diamond Gully?

The structure is 80 ft (24.4 m) long with a longest span of 20 ft (6.1 m) and a deck 43 ft wide.

Who owns US0171 over Diamond Gully?

It is owned by the State Highway Agency.