SR 687/4th Street over Big Island Gap
Pinellas County, Florida · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- SR 687/4th Street over Big Island Gap in Pinellas County, Florida, is rated in good condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 8 (very good condition) on the 0-9 scale.
- It was built in 2023, making it 2 years old at the 2025 inventory.
- It carries about 11,900 vehicles a day (traffic count year 2023).
- Its listed owner is the state highway agency.
- It is one of 287 of the 449 inventoried bridges in Pinellas County rated good (63.9%); 8 (1.8%) 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 August 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 → (27.89556, -82.63881)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 8 | 8 | Very good condition |
| Superstructure | 8 | 8 | Very good condition |
| Substructure | 8 | 8 | Very good condition |
Bridge details
| Structure | Prestressed concrete stringer or multi-beam girder |
| Length | about 263 ft |
| Location | 0.25MI S of I-275 |
| NBI structure number | 150309 |
| Condition class | Good |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | August 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 Florida department of transportation.
Busiest bridges in Pinellas County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I-275 SB over 30TH Ave North | 1974 | 158,000 | Good |
| I-275 SB over 22ND Avenue North | 1974 | 158,000 | Good |
| I-275 NB over 22ND Ave North | 1974 | 158,000 | Good |
| I-275 SB over 38TH Avenue North | 1974 | 158,000 | Good |
| I-275 NB over 38TH Avenue North | 1974 | 158,000 | Good |
| I-275 SB over 50TH Ave N SR-689 | 1972 | 155,500 | Good |
All bridges nearby: Pinellas County, FL bridge conditions · every bridge in Pinellas County · Florida bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.