FHWA NBI 2024 Inspection record Public-domain dataset

SR 309

Carrying SR 309 over BIG SLOUGH

4.5 MI. N.E. OF BAINBRIDG, Decatur, Georgia

Data updated May 2026

FHWA NBI record, refreshed with each annual release.

Good
34 t Inventory load rating

Bridge Snapshot: SR 309

The SR 309 bridge in Decatur, Georgia carries SR 309 over BIG SLOUGH. It was built in 1997, making it 29 years old today. The structure is built primarily of concrete and spans 8 sections, stretching 97.5 meters (320 feet) end to end. Daily traffic averages 1,560 vehicles, placing it in the moderately-trafficked tier of Georgia bridges. It is owned and maintained by State Highway Agency.

The latest FHWA inspection records show a deck rating of 7/9, superstructure at 7/9, substructure at 7/9. The weakest component sits in good condition. None of this bridge's reported major components fall into the Poor condition range. Its NBI inventory load rating is 34.4 metric tons.

Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.

How SR 309 compares

▲ 0.3
Load rating vs Georgia average (34.1 t)
Top 28%
Higher load rating than 72% of Georgia bridges
75
Bridges in Decatur · 1 in Poor condition
SR 309 34.4 t
Georgia average 34.1 t

Live comparison across Georgia.

Historical Sufficiency Rating

PlainBridge-computed
99.6 / 100 - historical 80–100 band
Structural adequacy /55
55.0
Serviceability /30
30.0
Essentiality /15
14.6
Special reductions
0

FHWA discontinued this calculated item; it does not determine current condition, funding eligibility, posting, or closure. How the historical reference is calculated.

Condition Ratings

Deck
7/9
Good (7–9)
Superstructure
7/9
Good (7–9)
Substructure
7/9
Good (7–9)
Inventory Load Rating
34.4 t
NBI inventory level (metric tons)
Overall Condition
Good

Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.

Structural Details

Year Built
1997
Material
Concrete
Number of Spans
8
Structure Length
97.5 m (320 ft)
Deck Width
12.6 m (41 ft)
Owner
State Highway Agency
Avg Daily Traffic
1,560 vehicles/day
Structure Number
000000008750570

Condition Analysis

  • At 7/9, the deck (driving surface) is in good shape and shows no significant wear.
  • The superstructure (beams and supports above the deck) is in good condition (7/9), showing no significant deterioration.
  • At 7/9, the substructure (piers and abutments) is in good shape and shows no significant wear.

How to read this record

This page shows what the last federal inspection recorded, not whether SR 309 is safe to cross today. Here is how to use it.

  • NBI condition ratings reflect the latest record in this annual dataset, not a live status. Current routine inspection intervals are risk-based.
  • Learn how the 0–9 condition scale and Good/Fair/Poor categories are defined. How condition ratings work
  • Compare SR 309 against other structures in Decatur and across Georgia. Georgia 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 SR 309?

SR 309 in Decatur, Georgia has a deck rating of 7/9, superstructure rating of 7/9, and substructure rating of 7/9 on the FHWA's 0–9 scale.

How often is SR 309 inspected?

SR 309'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 1,560 vehicles per day.

What does “structurally deficient” mean in older bridge reports?

FHWA retired that reported status beginning with the 2018 archive. SR 309 is currently shown as Good condition from its component ratings; that category is not a live closure or safety decision.

What is the inventory load rating for SR 309?

SR 309 has an NBI inventory load rating of 34.4 metric tons.

Who is responsible for maintaining SR 309?

SR 309 is owned and maintained by State Highway Agency.

How old is SR 309 and does age affect safety?

SR 309 was built in 1997, making it 29 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.

Data sourced from the Federal Highway Administration National Bridge Inventory. See our methodology for details. Retrieved and formatted by PlainBridges

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.