US-17 (SR-5) over St. Marys River
Nassau County, Florida · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- US-17 (SR-5) over St. Marys River in Nassau County, Florida, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the substructure, rated 5 (fair condition) on the 0-9 scale.
- It was built in 1927 and reconstructed in 2005, making it 98 years old at the 2025 inventory.
- It carries about 4,600 vehicles a day (traffic count year 2023).
- Its listed owner is the state highway agency.
- It is one of 51 of the 106 inventoried bridges in Nassau County rated fair (48.1%); 3 (2.8%) 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 April 2024, on a 24-month routine inspection cycle.
- It is coded scour critical (NBI item 113 = 3): scour critical: foundations unstable for the assessed or calculated scour.
- It has fracture-critical members (NBI item 92A): steel tension members without a redundant load path, which get their own scheduled inspections.
- A fair rating means the lowest-rated major component scores 5 or 6 on FHWA's 0-9 scale: some deterioration or minor section loss, but the structure is sound. It is the middle class, not a warning.
View this bridge on a map → (30.74166, -81.68797)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 7 | 7 | Good condition |
| Superstructure | 6 | 6 | Satisfactory condition |
| Substructure | 5 | 5 | Fair condition |
Bridge details
| Structure | Steel movable swing |
| Length | about 562 ft |
| Location | Fl. - Ga. State Line |
| NBI structure number | 740008 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | April 2024 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 3: scour critical: foundations unstable for the assessed or calculated scour |
| Fracture critical (item 92A) | Yes |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Florida department of transportation.
Busiest bridges in Nassau County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I-95 NB (SR-9) over St. Marys River | 1971 | 75,637 | Fair |
| I-95 (SR-9) over Lofton Creek | 1968 | 56,500 | Fair |
| I-95 (SR-9) over Cat Creek | 1968 | 56,500 | Fair |
| I-95 (sbl) over St Marys River | 1971 | 54,710 | Fair |
| SR-200 and A1A over Lofton Creek | 2019 | 45,500 | Good |
| I-95 SB (SR-9) over Sr-a1a & SR-200 | 1967 | 34,000 | Good |
All bridges nearby: Nassau County, FL bridge conditions · every bridge in Nassau County · Florida bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.