US Bridges

I 55 over Relief Slough

Fair

Yazoo County, Mississippi · 1.2 MI N Madison Cl · Structure no. 11000550821282B

Built
1969
56 years old
Condition
Fair
inspected June 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
400 ft
10 main spans
Daily traffic
10,000
2023 count
Owner
State
State Highway Agency

About this bridge

I 55 over Relief Slough is a prestressed concrete stringer/multi-beam or girder carrying I 55 over Relief Slough in Yazoo County, Mississippi. It was built in 1969, so it is 56 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.

It carries about 10,000 vehicles a day, roughly 24% of them trucks, projected to reach 13,000 by 2043. The structure is 400 ft (121.9 m) long and 44 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

CarriesI 55
CrossesRelief Slough
Location1.2 MI N Madison Cl
RouteInterstate 55
Coordinates32.75048, -90.06054
Functional classRural Principal Arterial - Interstate

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.
Superstructure8 Very GoodNo problems noted.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJune 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating61.7 US tons
Inventory rating37 US tons

Structure

MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans10
Design loadHS 20 + Mod
Structure length400 ft (121.9 m)
Longest span40 ft (12.2 m)
Deck width44 ft (13.4 m)
Roadway width40 ft (12.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic10,000 (2023)
Projected traffic13,000 by 2043
Trucks24%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesRelief for waterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was I 55 over Relief Slough built?

It was built in 1969, making it 56 years old in 2025.

What condition is I 55 over Relief Slough 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 June 2024.

How much traffic does I 55 over Relief Slough carry?

About 10,000 vehicles per day (2023 count), of which roughly 24% are trucks.

How long is I 55 over Relief Slough?

The structure is 400 ft (121.9 m) long with a longest span of 40 ft (12.2 m) and a deck 44 ft wide.

Who owns I 55 over Relief Slough?

It is owned by the State Highway Agency.