FDR 521
Carrying FDR 521 over FOUR MILE BRANCH
LOGMI 0.19 FR 532 TO, Grant, Louisiana
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: FDR 521
The FDR 521 bridge in Grant, Louisiana carries FDR 521 over FOUR MILE BRANCH. It was built in 1955, making it 71 years old today. The structure is built primarily of prestressed concrete and spans 2 sections, stretching 12.2 meters (40 feet) end to end. Daily traffic averages 26 vehicles, placing it in the lower-traffic tier of Louisiana bridges. It is owned and maintained by U.S. Forest Service.
The latest FHWA inspection records show a deck rating of 6/9, superstructure at 6/9, 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 13.9 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How FDR 521 compares
Live comparison across Louisiana.
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 How the historical reference is calculated.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
- Prestressed Concrete
- Number of Spans
- 2
- Structure Length
- 12.2 m (40 ft)
- Deck Width
- 4.2 m (14 ft)
- Owner
- U.S. Forest Service
- Avg Daily Traffic
- 26 vehicles/day
- Structure Number
- 080604000002417
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗Condition Analysis
- • The deck (driving surface) is in fair condition (6/9), with minor deterioration that may require routine maintenance.
- • The superstructure (beams and supports above the deck) rates fair at 6/9, minor deterioration that routine maintenance should address.
- • At 4/9, the substructure (piers and abutments) is in poor shape, with advanced wear flagged for priority repair.
How to read this record
FDR 521 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 FDR 521 against other structures in Grant and across Louisiana. Louisiana 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 FDR 521?
FDR 521 in Grant, Louisiana has a deck rating of 6/9, superstructure rating of 6/9, and substructure rating of 4/9 on the FHWA's 0–9 scale.
How often is FDR 521 inspected?
FDR 521'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 26 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. FDR 521 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 FDR 521?
FDR 521 has an NBI inventory load rating of 13.9 metric tons.
Who is responsible for maintaining FDR 521?
FDR 521 is owned and maintained by U.S. Forest Service.
How old is FDR 521 and does age affect safety?
FDR 521 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.