US 17 ALT
Carrying US 17 ALT over COMBAHEE RIVER
HAMP/COLL CO LN, Colleton, South Carolina
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: US 17 ALT
The US 17 ALT bridge in Colleton, South Carolina carries US 17 ALT over COMBAHEE RIVER. It was built in 1940, making it 86 years old today. The structure is built primarily of concrete and spans 27 sections, stretching 246.9 meters (810 feet) end to end. Daily traffic averages 1,300 vehicles, placing it in the moderately-trafficked tier of South Carolina bridges. It is owned and maintained by State Highway Agency.
The latest FHWA inspection records show a deck rating of 5/9, superstructure at 4/9, substructure at 4/9. The weakest component sits in poor condition. At least one major component here scores 4 or below, which produces a Poor condition classification under FHWA's current reporting rules. Its NBI inventory load rating is 26.2 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How US 17 ALT compares
Live comparison across South Carolina.
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 How the historical reference is calculated.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
- 1940
- Material
- Concrete
- Number of Spans
- 27
- Structure Length
- 246.9 m (810 ft)
- Deck Width
- 8.4 m (28 ft)
- Owner
- State Highway Agency
- Avg Daily Traffic
- 1,300 vehicles/day
- Structure Number
- 000000000001026
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗Condition Analysis
- • The deck (driving surface) rates fair at 5/9, minor deterioration that routine maintenance should address.
- • At 4/9, the superstructure (beams and supports above the deck) is in poor shape, with advanced wear flagged for priority repair.
- • The substructure (piers and abutments) rates poor at 4/9, advanced deterioration that should be prioritized for repair.
How to read this record
US 17 ALT 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 US 17 ALT against other structures in Colleton 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 US 17 ALT?
US 17 ALT in Colleton, South Carolina has a deck rating of 5/9, superstructure rating of 4/9, and substructure rating of 4/9 on the FHWA's 0–9 scale.
How often is US 17 ALT inspected?
US 17 ALT'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 1,300 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. US 17 ALT 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 US 17 ALT?
US 17 ALT has an NBI inventory load rating of 26.2 metric tons.
Who is responsible for maintaining US 17 ALT?
US 17 ALT is owned and maintained by State Highway Agency.
How old is US 17 ALT and does age affect safety?
US 17 ALT was built in 1940, making it 86 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.