US Bridges

SR 12 over Granicus Bayou

FairPosted for load

Washington County, Mississippi · 7.9 MI E SR 1 · Structure no. 310001207600790

Built
1959
66 years old
Condition
Fair
inspected November 2024
Type
Slab
Concrete
Length
120 ft
4 main spans
Daily traffic
600
2023 count
Owner
State
State Highway Agency

About this bridge

SR 12 over Granicus Bayou is a concrete slab carrying SR 12 over Granicus Bayou in Washington County, Mississippi. It was built in 1959, so it is 66 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 600 vehicles a day, roughly 11% of them trucks, projected to reach 600 by 2043. The structure is 120 ft (36.6 m) long and 31 ft wide. If it were closed, the detour would be 23 mi (37 km).

Location

Open in Google Maps
CarriesSR 12
CrossesGranicus Bayou
Location7.9 MI E SR 1
RouteState Highway 12
CountyWashington County
StateMississippi
Coordinates33.16049, -90.94848
Functional classRural Minor Arterial

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 protection8 Very GoodNo problems noted.
Last inspectionNovember 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating42.8 US tons
Inventory rating25.6 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans4
Design loadHS 15
Structure length120 ft (36.6 m)
Longest span30 ft (9.1 m)
Deck width31 ft (9.4 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic600 (2023)
Projected traffic600 by 2043
Trucks11%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed23 mi (37 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$474 million
NavigationNo navigation control on waterway

Frequently asked questions

When was SR 12 over Granicus Bayou built?

It was built in 1959, making it 66 years old in 2025.

What condition is SR 12 over Granicus Bayou 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 November 2024.

How much traffic does SR 12 over Granicus Bayou carry?

About 600 vehicles per day (2023 count), of which roughly 11% are trucks.

How long is SR 12 over Granicus Bayou?

The structure is 120 ft (36.6 m) long with a longest span of 30 ft (9.1 m) and a deck 31 ft wide.

Who owns SR 12 over Granicus Bayou?

It is owned by the State Highway Agency.