FHWA NBI 2024 Inspection record Public-domain dataset

S-21-646

Carrying S-21-646 over SINGLETARY BRANCH

TOWN OF COWARD, Florence, South Carolina

Data updated May 2026

FHWA NBI record, refreshed with each annual release.

Good
45 t Inventory load rating

Bridge Snapshot: S-21-646

The S-21-646 bridge in Florence, South Carolina carries S-21-646 over SINGLETARY BRANCH. It was built in 1996, making it 30 years old today. The structure is built primarily of concrete continuous and spans 3 sections, stretching 21.0 meters (69 feet) end to end. Daily traffic averages 125 vehicles, placing it in the lower-traffic tier of South Carolina 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 8/9. 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 45.0 metric tons.

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

How S-21-646 compares

▲ 15.2
Load rating vs South Carolina average (29.8 t)
Top 10%
Higher load rating than 90% of South Carolina bridges
161
Bridges in Florence · 3 in Poor condition
S-21-646 45.0 t
South Carolina average 29.8 t

Live comparison across South Carolina.

Historical Sufficiency Rating

PlainBridge-computed
100.0 / 100 - historical 80–100 band
Structural adequacy /55
55.0
Serviceability /30
30.0
Essentiality /15
15.0
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 How the historical reference is calculated.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
8/9
Good (7–9)
Inventory Load Rating
45.0 t
NBI inventory level (metric tons)
Overall Condition
Good

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

Structural Details

Year Built
1996
Material
Concrete Continuous
Number of Spans
3
Structure Length
21.0 m (69 ft)
Deck Width
11.1 m (36 ft)
Owner
State Highway Agency
Avg Daily Traffic
125 vehicles/day
Structure Number
000000000009007

Condition Analysis

  • The deck (driving surface) is in good condition (7/9), showing no significant deterioration.
  • The superstructure (beams and supports above the deck) rates good at 7/9, with no significant deterioration on file.
  • The substructure (piers and abutments) rates good at 8/9, with no significant deterioration on file.

How to read this record

This page shows what the last federal inspection recorded, not whether S-21-646 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 S-21-646 against other structures in Florence and across South Carolina. South Carolina 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 S-21-646?

S-21-646 in Florence, South Carolina has a deck rating of 7/9, superstructure rating of 7/9, and substructure rating of 8/9 on the FHWA's 0–9 scale.

How often is S-21-646 inspected?

S-21-646'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 125 vehicles per day.

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

FHWA retired that reported status beginning with the 2018 archive. S-21-646 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 S-21-646?

S-21-646 has an NBI inventory load rating of 45.0 metric tons.

Who is responsible for maintaining S-21-646?

S-21-646 is owned and maintained by State Highway Agency.

How old is S-21-646 and does age affect safety?

S-21-646 was built in 1996, making it 30 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.