US Bridges

LA1090 over I-59

Fair

St. Tammany Parish, Louisiana · LA1090 · Structure no. 625208522606851

Built
1963
62 years old
Condition
Fair
inspected August 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
313 ft
4 main spans
Daily traffic
9,260
2021 count
Owner
State
State Highway Agency

About this bridge

LA1090 over I-59 is a steel stringer/multi-beam or girder carrying LA1090 over I-59 in St. Tammany Parish, Louisiana. It was built in 1963, so it is 62 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 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 9,260 vehicles a day, roughly 8% of them trucks, projected to reach 10,186 by 2041. The structure is 313 ft (95.4 m) long and 30 ft wide.

Location

Open in Google Maps
CarriesLA1090
CrossesI-59
LocationLA1090
RouteState Highway 1090
CountySt. Tammany Parish
StateLouisiana
Coordinates30.35301, -89.7402
Functional classUrban 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.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating72 US tons
Inventory rating43 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length313 ft (95.4 m)
Longest span100 ft (30.5 m)
Deck width30 ft (9.1 m)
Roadway width29 ft (8.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic9,260 (2021)
Projected traffic10,186 by 2041
Trucks8%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed—
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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was LA1090 over I-59 built?

It was built in 1963, making it 62 years old in 2025.

What condition is LA1090 over I-59 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 August 2023.

How much traffic does LA1090 over I-59 carry?

About 9,260 vehicles per day (2021 count), of which roughly 8% are trucks.

How long is LA1090 over I-59?

The structure is 313 ft (95.4 m) long with a longest span of 100 ft (30.5 m) and a deck 30 ft wide.

Who owns LA1090 over I-59?

It is owned by the State Highway Agency.