Structure 24504503700001 · St. Charles County, LA

I0310 over Mississippi River

Carries I0310 over Mississippi River, 4.4 Mi S Of US 61.

Overall conditionFair

Set by its lowest-rated component: Substructure at 5 of 9.

How ratings work
Deck6/9 · Satisfactory
Superstructure6/9 · Satisfactory
Substructuresets the rating5/9 · Fair
Channelnot part of overall8/9 · Very Good
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT2,745 FT OVERALL500 FT0ELEVATION · LENGTHS TO SCALE
Deck 6/9Superstructure 6/9Substructure 5/9 · sets the rating

2,745 ft end to end, longest span 1,235 ft: about 7.6 football fields. Lengths and the semi-truck on the deck are drawn to the same scale. Each part is colored by its latest inspection rating. The inventory records lengths but not heights or the layout of the shorter spans, so those are drawn as typical for a cable-stayed bridge.

Built198343 years old
Length2745.1 ft836.7 m
Daily traffic47,396counted 2021
Last inspectedFebruary 2023every 24 months

Location

StateLouisiana
CountySt. Charles
Location4.4 Mi S Of US 61
CarriesI0310
CrossesMississippi River
Coordinates29.94460, -90.37292

Physical Characteristics

MaterialSteel Continuous
DesignStayed Girder
Total Length2745.1 ft (836.7 m)
Max Span1234.9 ft (376.4 m)
Deck Width92.5 ft (28.2 m)
Deck Area23594.9 sq m
Main Spans5
Year Built1983

Traffic

Avg Daily Traffic47,396 (2021)
Truck Traffic25%
Lanes On Bridge4

Inspection & Ownership

Last InspectionFebruary 2023
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour Critical7 — Countermeasures installed
Structure Number024504503700001

How Bridge Ratings Work

Inspectors rate each major part of a bridge (the deck you drive on, the superstructure of beams that holds it up, and the substructure of piers and abutments beneath) on a 0–9 scale. A bridge's overall condition is its lowest of those ratings, so one deteriorated component makes the whole bridge "poor."

0Failed
1Imminent failure
2Critical
3Serious
4Poor
5Fair
6Satisfactory
7Good
8Very good
9Excellent
Good · lowest component 7–9
Fair · lowest component 5–6
Poor · lowest component 0–4

A poor rating is not a closure. It means the bridge is flagged for priority repair or replacement; bridges judged unsafe are closed or posted with weight limits. The waterway (channel) rating is reported, but it does not count toward the overall classification.

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