US Bridges

SR 178 over Mantachie Canal

FairPosted for load

Itawamba County, Mississippi · 4.6 MI E Lee Cl · Structure no. 310017802910270

Built
1949
76 years old
Condition
Fair
inspected September 2024
Type
Truss - Thru
Steel
Length
312 ft
1 main span
Daily traffic
2,300
2023 count
Owner
State
State Highway Agency

About this bridge

SR 178 over Mantachie Canal is a steel truss - thru carrying SR 178 over Mantachie Canal in Itawamba County, Mississippi. It was built in 1949, so it is 76 years old, older than the Mississippi average of 38.9 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. Its operating status is: posted for load restriction.

It carries about 2,300 vehicles a day, roughly 2% of them trucks, projected to reach 2,300 by 2043. The structure is 312 ft (95.1 m) long and 28 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

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CarriesSR 178
CrossesMantachie Canal
Location4.6 MI E Lee Cl
RouteState Highway 178
CountyItawamba County
StateMississippi
Coordinates34.25261, -88.47686
Functional classRural Major Collector

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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionSeptember 2024
Inspection intervalevery 12 months
Operating statusPosted for load restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating39 US tons
Inventory rating23.3 US tons

Structure

Structure typeTruss - Thru
MaterialSteel
DeckConcrete, cast-in-place
Main spans1 (+4 approach)
Design loadHS 15
Structure length312 ft (95.1 m)
Longest span152 ft (46.3 m)
Deck width28 ft (8.5 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deck15 ft (4.5 m)

Traffic and service

Average daily traffic2,300 (2023)
Projected traffic2,300 by 2043
Trucks2%
Lanes on structure20
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$1,000 million
NavigationNo navigation control on waterway

Frequently asked questions

When was SR 178 over Mantachie Canal built?

It was built in 1949, making it 76 years old in 2025.

What condition is SR 178 over Mantachie Canal 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 September 2024.

How much traffic does SR 178 over Mantachie Canal carry?

About 2,300 vehicles per day (2023 count), of which roughly 2% are trucks.

How long is SR 178 over Mantachie Canal?

The structure is 312 ft (95.1 m) long with a longest span of 152 ft (46.3 m) and a deck 28 ft wide.

Who owns SR 178 over Mantachie Canal?

It is owned by the State Highway Agency.