US Bridges

Mira-Myrtis RD over Big Branch

Fair

Caddo Parish, Louisiana · 2 Mi. W of US71 · Structure no. 040932562935521

Built
1948
77 years old
Condition
Fair
inspected February 2025
Type
Slab
Concrete
Length
40 ft
3 main spans
Daily traffic
40
2019 count
Owner
County
County Highway Agency

About this bridge

Mira-Myrtis RD over Big Branch is a concrete slab carrying Mira-Myrtis RD over Big Branch in Caddo Parish, Louisiana. It was built in 1948, so it is 77 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 40 vehicles a day, projected to reach 44 by 2039. The structure is 40 ft (12.2 m) long and 22 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesMira-Myrtis RD
CrossesBig Branch
Location2 Mi. W of US71
RouteCounty Highway 0
CountyCaddo Parish
StateLouisiana
Coordinates32.93644, -93.91966
Functional classRural 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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionFebruary 2025
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating39.2 US tons
Inventory rating30.3 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 15
Structure length40 ft (12.2 m)
Longest span25 ft (7.6 m)
Deck width22 ft (6.6 m)
Roadway width20 ft (6.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic40 (2019)
Projected traffic44 by 2039
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 statusNot eligible for the National Register of Historic Places
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$168,000
NavigationNo navigation control on waterway

Frequently asked questions

When was Mira-Myrtis RD over Big Branch built?

It was built in 1948, making it 77 years old in 2025.

What condition is Mira-Myrtis RD over Big Branch 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 2025.

How much traffic does Mira-Myrtis RD over Big Branch carry?

About 40 vehicles per day (2019 count).

How long is Mira-Myrtis RD over Big Branch?

The structure is 40 ft (12.2 m) long with a longest span of 25 ft (7.6 m) and a deck 22 ft wide.

Who owns Mira-Myrtis RD over Big Branch?

It is owned by the County Highway Agency.