US Bridges

US 51 over Big Black River

FairPosted for load

Madison County, Mississippi · 1.3 MI N SR 17 · Structure no. 210005104513940

Built
1939
86 years old
Condition
Fair
inspected May 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
1,385 ft
3 main spans
Daily traffic
930
2023 count
Owner
State
State Highway Agency

About this bridge

US 51 over Big Black River is a steel continuous stringer/multi-beam or girder carrying US 51 over Big Black River in Madison County, Mississippi. It was built in 1939, so it is 86 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 6 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 930 vehicles a day, roughly 11% of them trucks, projected to reach 930 by 2043. The structure is 1,385 ft (422.1 m) long and 26 ft wide. If it were closed, the detour would be 36 mi (58 km).

Location

Open in Google Maps
CarriesUS 51
CrossesBig Black River
Location1.3 MI N SR 17
RouteU.S. Route 51
CountyMadison County
StateMississippi
Coordinates32.86629, -89.97416
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionMay 2024
Inspection intervalevery 12 months
Operating statusPosted for load restriction
ScourScour evaluation has not been made
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 adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating24.1 US tons
Inventory rating17.1 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3 (+47 approach)
Design loadH 15
Structure length1,385 ft (422.1 m)
Longest span90 ft (27.4 m)
Deck width26 ft (8 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic930 (2023)
Projected traffic930 by 2043
Trucks11%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed36 mi (58 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 proposedWidening with deck rehabilitation or replacement
Estimated improvement cost$1,000 million
NavigationNo navigation control on waterway

Frequently asked questions

When was US 51 over Big Black River built?

It was built in 1939, making it 86 years old in 2025.

What condition is US 51 over Big Black River 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 May 2024.

How much traffic does US 51 over Big Black River carry?

About 930 vehicles per day (2023 count), of which roughly 11% are trucks.

How long is US 51 over Big Black River?

The structure is 1,385 ft (422.1 m) long with a longest span of 90 ft (27.4 m) and a deck 26 ft wide.

Who owns US 51 over Big Black River?

It is owned by the State Highway Agency.