US Bridges

I0020 over Mack-Bayou

Fair

Madison Parish, Louisiana · 2.6 MI East of LA 577 · Structure no. 053304510805391

Built
1975
50 years old
Condition
Fair
inspected June 2023
Type
Culvert
Concrete
Length
38 ft
5 main spans
Daily traffic
31,481
2021 count
Owner
State
State Highway Agency

About this bridge

I0020 over Mack-Bayou is a concrete culvert carrying I0020 over Mack-Bayou in Madison Parish, Louisiana. It was built in 1975, so it is 50 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 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 31,481 vehicles a day, roughly 37% of them trucks, projected to reach 34,629 by 2041. The structure is 38 ft (11.6 m) long and 214 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

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CarriesI0020
CrossesMack-Bayou
Location2.6 MI East of LA 577
RouteInterstate 20
CountyMadison Parish
StateLouisiana
Coordinates32.42565, -91.3815
Functional classRural Principal Arterial - Interstate

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry9: Superior to present desirable criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating44 US tons
Inventory rating34 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckNot applicable
Main spans5
Design loadHS 20
Structure length38 ft (11.6 m)
Longest span7 ft (2.1 m)
Deck width214 ft (65.2 m)
Roadway width84 ft (25.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic31,481 (2021)
Projected traffic34,629 by 2041
Trucks37%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

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 I0020 over Mack-Bayou built?

It was built in 1975, making it 50 years old in 2025.

What condition is I0020 over Mack-Bayou 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 June 2023.

How much traffic does I0020 over Mack-Bayou carry?

About 31,481 vehicles per day (2021 count), of which roughly 37% are trucks.

How long is I0020 over Mack-Bayou?

The structure is 38 ft (11.6 m) long with a longest span of 7 ft (2.1 m) and a deck 214 ft wide.

Who owns I0020 over Mack-Bayou?

It is owned by the State Highway Agency.