I0055 over I-55 Off Ramp @ US 51
St. John the Baptist Parish, Louisiana · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- I0055 over I-55 Off Ramp @ US 51 in St. John the Baptist Parish, Louisiana, is rated in good condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 7 (good condition) on the 0-9 scale.
- It was built in 1975, making it 50 years old at the 2025 inventory.
- It carries about 15,642 vehicles a day (traffic count year 2021).
- Its listed owner is the state highway agency.
- It is one of 13 of the 40 inventoried bridges in St. John the Baptist Parish rated good (32.5%); 1 (2.5%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- Its condition class and component ratings are unchanged from the 2024 inventory.
- Its most recent inspection on record is dated June 2023, on a 24-month routine inspection cycle.
- A good rating means every major component - deck, superstructure, substructure, or culvert - is rated 7 or higher on FHWA's 0-9 scale: no more than minor problems.
View this bridge on a map → (30.09481, -90.439)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 7 | 7 | Good condition |
| Superstructure | 8 | 8 | Very good condition |
| Substructure | 7 | 7 | Good condition |
Bridge details
| Structure | Prestressed concrete stringer or multi-beam girder |
| Length | about 674 ft |
| Location | 0.1 M N of US 51 |
| NBI structure number | 624804520100908 |
| Condition class | Good |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | June 2023 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 8: foundations stable, scour above the top of the footing |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Louisiana department of transportation.
Busiest bridges in St. John the Baptist Parish
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I0010 over US 51 & Swamps | 1972 | 48,723 | Fair |
| I0010 over Hope Canal | 1975 | 44,074 | Fair |
| I0010 over Mississippi Bayou | 1975 | 44,074 | Fair |
| I0010 over Reserve Relief Canal | 1974 | 44,074 | Fair |
| I0055 over Swamp | 1975 | 28,021 | Good |
| I0055 over Swamp | 2008 | 27,551 | Fair |
All bridges nearby: St. John the Baptist Parish, LA bridge conditions · every bridge in St. John the Baptist Parish · Louisiana bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.