US Bridges

Mt Plesant Zachary over Cooper Bayou

Fair

East Baton Rouge Parish, Louisiana · 1.25 MI West US 61 Int. · Structure no. 611730385911551

Built
1966
59 years old
Condition
Fair
inspected January 2024
Type
Slab
Concrete
Length
100 ft
5 main spans
Daily traffic
114
2023 count
Owner
County
County Highway Agency

About this bridge

Mt Plesant Zachary over Cooper Bayou is a concrete slab carrying Mt Plesant Zachary over Cooper Bayou in East Baton Rouge Parish, Louisiana. It was built in 1966, so it is 59 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 114 vehicles a day, projected to reach 125 by 2043. The structure is 100 ft (30.5 m) long and 29 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

Location

Open in Google Maps
CarriesMt Plesant Zachary
CrossesCooper Bayou
Location1.25 MI West US 61 Int.
RouteCounty Highway 0
CountyEast Baton Rouge Parish
StateLouisiana
Coordinates30.64698, -91.26483
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 protection7 GoodSome minor problems.
Last inspectionJanuary 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
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 rating29.7 US tons
Inventory rating22.8 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans5
Design loadHS 20
Structure length100 ft (30.5 m)
Longest span20 ft (6.1 m)
Deck width29 ft (8.8 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic114 (2023)
Projected traffic125 by 2043
Trucks—
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

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 Mt Plesant Zachary over Cooper Bayou built?

It was built in 1966, making it 59 years old in 2025.

What condition is Mt Plesant Zachary over Cooper 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 January 2024.

How much traffic does Mt Plesant Zachary over Cooper Bayou carry?

About 114 vehicles per day (2023 count).

How long is Mt Plesant Zachary over Cooper Bayou?

The structure is 100 ft (30.5 m) long with a longest span of 20 ft (6.1 m) and a deck 29 ft wide.

Who owns Mt Plesant Zachary over Cooper Bayou?

It is owned by the County Highway Agency.