US Bridges

Smith Co. 120 over Leaf River

Good

Smith County, Mississippi · SEC_18_T 3N_R 9E B · Structure no. SA6500000000159

Built
2012
13 years old
Condition
Good
inspected October 2024
Type
Stringer/Multi-beam or Girder
Concrete
Length
320 ft
700 main spans
Daily traffic
170
2024 count
Owner
County
County Highway Agency

About this bridge

Smith Co. 120 over Leaf River is a concrete stringer/multi-beam or girder carrying Smith Co. 120 over Leaf River in Smith County, Mississippi. It was built in 2012, so it is 13 years old, younger than the Mississippi average of 38.9 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 170 vehicles a day, roughly 25% of them trucks, projected to reach 255 by 2044. The structure is 320 ft (97.5 m) long and 31 ft wide. If it were closed, the detour would be 8.1 mi (13 km).

CarriesSmith Co. 120
CrossesLeaf River
LocationSEC_18_T 3N_R 9E B
RouteCounty Highway 163
Coordinates32.10367, -89.42056
Functional classRural Local

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating64 US tons
Inventory rating31 US tons

Structure

MaterialConcrete
DeckConcrete, cast-in-place
Main spans700
Design loadHS 20
Structure length320 ft (97.5 m)
Longest span80 ft (24.4 m)
Deck width31 ft (9.4 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic170 (2024)
Projected traffic255 by 2044
Trucks25%
Lanes on structure20
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed8.1 mi (13 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$2.1 million (2024 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Smith Co. 120 over Leaf River built?

It was built in 2012, making it 13 years old in 2025.

What condition is Smith Co. 120 over Leaf River in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in October 2024.

How much traffic does Smith Co. 120 over Leaf River carry?

About 170 vehicles per day (2024 count), of which roughly 25% are trucks.

How long is Smith Co. 120 over Leaf River?

The structure is 320 ft (97.5 m) long with a longest span of 80 ft (24.4 m) and a deck 31 ft wide.

Who owns Smith Co. 120 over Leaf River?

It is owned by the County Highway Agency.