US Bridges

Sontheimer RD over I-12

Fair

Tangipahoa Parish, Louisiana · I0012 · Structure no. 625304540311101

Built
1975
50 years old
Condition
Fair
inspected February 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
266 ft
4 main spans
Daily traffic
4,830
2015 count
Owner
State
State Highway Agency

About this bridge

Sontheimer RD over I-12 is a prestressed concrete stringer/multi-beam or girder carrying Sontheimer RD over I-12 in Tangipahoa Parish, Louisiana. It was built in 1975, so it is 50 years old, older than the Louisiana average of 43 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.

It carries about 4,830 vehicles a day, projected to reach 5,313 by 2035. The structure is 266 ft (81.1 m) long and 30 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

Location

Open in Google Maps
CarriesSontheimer RD
CrossesI-12
LocationI0012
RouteCounty Highway 0
CountyTangipahoa Parish
StateLouisiana
Coordinates30.47853, -90.3728
Functional classRural Local

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure8 Very GoodNo problems noted.
Last inspectionFebruary 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Approach roadway alignment8: Equal to present desirable criteria
Operating rating67 US tons
Inventory rating34 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length266 ft (81.1 m)
Longest span88 ft (26.8 m)
Deck width30 ft (9.1 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,830 (2015)
Projected traffic5,313 by 2035
Trucks—
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed98.8 mi (159 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$1.2 million
NavigationNot applicable (no waterway)

Frequently asked questions

When was Sontheimer RD over I-12 built?

It was built in 1975, making it 50 years old in 2025.

What condition is Sontheimer RD over I-12 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 February 2023.

How much traffic does Sontheimer RD over I-12 carry?

About 4,830 vehicles per day (2015 count).

How long is Sontheimer RD over I-12?

The structure is 266 ft (81.1 m) long with a longest span of 88 ft (26.8 m) and a deck 30 ft wide.

Who owns Sontheimer RD over I-12?

It is owned by the State Highway Agency.