US Bridges

LA1085 over I-12

Good

St. Tammany Parish, Louisiana · LA1085 · Structure no. 625208520203191

Built
1975
50 years old
Condition
Good
inspected August 2023
Type
Girder and Floorbeam System
Steel Continuous
Length
368 ft
4 main spans
Daily traffic
6,010
2021 count
Owner
State
State Highway Agency

About this bridge

LA1085 over I-12 is a steel continuous girder and floorbeam system carrying LA1085 over I-12 in St. Tammany 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 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 6,010 vehicles a day, roughly 9% of them trucks, projected to reach 6,611 by 2041. The structure is 368 ft (112.2 m) long and 30 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

Location

Open in Google Maps
CarriesLA1085
CrossesI-12
LocationLA1085
RouteState Highway 1085
CountySt. Tammany Parish
StateLouisiana
Coordinates30.46412, -90.2013
Functional classUrban Collector

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.
Superstructure7 GoodSome minor problems.
Substructure8 Very GoodNo problems noted.
Last inspectionAugust 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 rating44 US tons
Inventory rating26 US tons

Structure

Structure typeGirder and Floorbeam System
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length368 ft (112.2 m)
Longest span113 ft (34.4 m)
Deck width30 ft (9.1 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic6,010 (2021)
Projected traffic6,611 by 2041
Trucks9%
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$1.6 million
NavigationNot applicable (no waterway)

Frequently asked questions

When was LA1085 over I-12 built?

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

What condition is LA1085 over I-12 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 August 2023.

How much traffic does LA1085 over I-12 carry?

About 6,010 vehicles per day (2021 count), of which roughly 9% are trucks.

How long is LA1085 over I-12?

The structure is 368 ft (112.2 m) long with a longest span of 113 ft (34.4 m) and a deck 30 ft wide.

Who owns LA1085 over I-12?

It is owned by the State Highway Agency.