US Bridges

LA0173 over Mahlin Bayou

PoorPosted for load

Caddo Parish, Louisiana · .48 MI East of LA 1 · Structure no. 040900940200481

Built
1965
60 years old
Condition
Poor
inspected January 2024
Type
Slab
Concrete
Length
76 ft
4 main spans
Daily traffic
713
2021 count
Owner
State
State Highway Agency

About this bridge

LA0173 over Mahlin Bayou is a concrete slab carrying LA0173 over Mahlin Bayou in Caddo Parish, Louisiana. It was built in 1965, so it is 60 years old, older than the Louisiana average of 43 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. Its operating status is: posted for load restriction.

It carries about 713 vehicles a day, roughly 19% of them trucks, projected to reach 784 by 2041. The structure is 76 ft (23.2 m) long and 28 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesLA0173
CrossesMahlin Bayou
Location.48 MI East of LA 1
RouteState Highway 173
CountyCaddo Parish
StateLouisiana
Coordinates32.6338, -93.8842
Functional classRural Major Collector

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck4 PoorAdvanced section loss, deterioration, spalling or scour.
Superstructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Substructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJanuary 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating17.9 US tons
Inventory rating13.9 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, precast panels
Main spans4
Design loadHS 20
Structure length76 ft (23.2 m)
Longest span19 ft (5.8 m)
Deck width28 ft (8.4 m)
Roadway width24 ft (7.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic713 (2021)
Projected traffic784 by 2041
Trucks19%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState 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$393,000
NavigationNo navigation control on waterway

Frequently asked questions

When was LA0173 over Mahlin Bayou built?

It was built in 1965, making it 60 years old in 2025.

What condition is LA0173 over Mahlin Bayou in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in January 2024.

How much traffic does LA0173 over Mahlin Bayou carry?

About 713 vehicles per day (2021 count), of which roughly 19% are trucks.

How long is LA0173 over Mahlin Bayou?

The structure is 76 ft (23.2 m) long with a longest span of 19 ft (5.8 m) and a deck 28 ft wide.

Who owns LA0173 over Mahlin Bayou?

It is owned by the State Highway Agency.