SR390
Carrying SR390 over Mill Bayou
1.2 Miles West of US231, Bay, Florida
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: SR390
The SR390 bridge in Bay, Florida carries SR390 over Mill Bayou. It was built in 1955, making it 71 years old today. The structure is built primarily of concrete and spans 6 sections, stretching 45.7 meters (150 feet) end to end. Daily traffic averages 9,100 vehicles, placing it in the moderately-trafficked tier of Florida bridges. It is owned and maintained by State Highway Agency.
The latest FHWA inspection records show a deck rating of 6/9, superstructure at 5/9, substructure at 4/9. The weakest component sits in poor condition. A component scored 4 or below, placing this bridge in the federal Poor condition category rather than declaring it unsafe or closed. Its NBI inventory load rating is 21.8 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How SR390 compares
Live comparison across Florida.
Historical Sufficiency Rating
PlainBridge-computedFHWA discontinued this calculated item; it does not determine current condition, funding eligibility, posting, or closure. How the historical reference is calculated.
Condition Ratings
Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.
Structural Details
- Year Built
- 1955
- Material
- Concrete
- Number of Spans
- 6
- Structure Length
- 45.7 m (150 ft)
- Deck Width
- 8.9 m (29 ft)
- Owner
- State Highway Agency
- Avg Daily Traffic
- 9,100 vehicles/day
- Structure Number
- 460020
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗Condition Analysis
- • The deck (driving surface) rates fair at 6/9, minor deterioration that routine maintenance should address.
- • At 5/9, the superstructure (beams and supports above the deck) shows fair condition, with minor wear flagged for upkeep.
- • The substructure (piers and abutments) is in poor condition (4/9), showing advanced deterioration that may require priority repair.
How to read this record
SR390 is in the federal Poor condition category. That is a component-based result, not a closure order.
- NBI condition ratings reflect the latest record in this annual dataset, not a live status. Current routine inspection intervals are risk-based.
- Understand what Poor condition does and does not mean before drawing conclusions. Poor condition explained
- Compare SR390 against other structures in Bay and across Florida. Florida bridges
- Noticed visible damage or a safety concern? Report it to the agency that owns the bridge, or call 911 in an emergency. How to report a bridge
Condition codes come straight from the FHWA National Bridge Inventory and are not a real-time safety judgment. Only the owning agency, a state DOT, county, or other owner, can post, restrict, or close a bridge.
Frequently Asked Questions
What do the condition ratings mean for SR390?
SR390 in Bay, Florida has a deck rating of 6/9, superstructure rating of 5/9, and substructure rating of 4/9 on the FHWA's 0–9 scale.
How often is SR390 inspected?
SR390's responsible agency sets its routine interval under FHWA's risk-based inspection rules; this page does not expose the scheduled interval. It carries about 9,100 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. SR390 is currently shown as Poor condition from its component ratings; that category is not a live closure or safety decision.
What is the inventory load rating for SR390?
SR390 has an NBI inventory load rating of 21.8 metric tons.
Who is responsible for maintaining SR390?
SR390 is owned and maintained by State Highway Agency.
How old is SR390 and does age affect safety?
SR390 was built in 1955, making it 71 years old.
Disclaimer: Bridge condition data is from the FHWA NBI and reflects the last reported inspection. A Poor condition rating is not a live declaration that a bridge is closed or unsafe for travel. For current closure, posting, or safety information, contact the responsible transportation agency.
Every figure on PlainBridge is rendered directly from federal source data, no number is typed in by an editor. This page draws directly on federal source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.