Guste Island Rd over Black Bayou
St. Tammany Parish, Louisiana · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Guste Island Rd over Black Bayou in St. Tammany 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 1984, making it 41 years old at the 2025 inventory.
- It carries about 200 vehicles a day (traffic count year 2018).
- Its listed owner is the county highway agency.
- It is one of 123 of the 361 inventoried bridges in St. Tammany Parish rated good (34.1%); 18 (5.0%) 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 July 2024, 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 → (30.40119, -90.21849)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 7 | 7 | Good condition |
| Superstructure | 7 | 7 | Good condition |
| Substructure | 7 | 7 | Good condition |
Bridge details
| Structure | Concrete slab |
| Length | about 132 ft |
| Location | 2.36 Mi. S. of LA 22 |
| NBI structure number | 625200000620355 |
| Condition class | Good |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | July 2024 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | U: unknown foundation, not evaluated for scour |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Louisiana department of transportation.
Busiest bridges in St. Tammany Parish
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I0010 over East Pearl River | 1966 | 87,741 | Fair |
| I0010 over La 433 | 1966 | 82,860 | Fair |
| I0010 over Canal | 1966 | 82,860 | Fair |
| I0012 over La 59 | 1976 | 80,162 | Good |
| I0012 over Ponchatolawa Creek | 1976 | 79,960 | Fair |
| I0012 over Tchefuncte River | 1975 | 79,563 | Fair |
All bridges nearby: St. Tammany Parish, LA bridge conditions · every bridge in St. Tammany Parish · Louisiana bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.