397TH AVE.
Carrying 397TH AVE. over MORRIS CK
7.1S WOONSOCKET, Sanborn, South Dakota
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: 397TH AVE.
The 397TH AVE. bridge in Sanborn, South Dakota carries 397TH AVE. over MORRIS CK. It was built in 1930, making it 96 years old today. It was last reconstructed in 1960, extending its service life. The structure is built primarily of steel and spans 1 section, stretching 7.9 meters (26 feet) end to end. Daily traffic averages 225 vehicles, placing it in the lower-traffic tier of South Dakota bridges. It is owned and maintained by County Highway Agency.
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. 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 21.3 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How 397TH AVE. compares
Live comparison across South Dakota.
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 How the historical reference is calculated.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
- 1930
- Last Reconstructed
- 1960
- Material
- Steel
- Number of Spans
- 1
- Structure Length
- 7.9 m (26 ft)
- Deck Width
- 9.9 m (32 ft)
- Owner
- County Highway Agency
- Avg Daily Traffic
- 225 vehicles/day
- Structure Number
- 000000056030171
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 6/9, the superstructure (beams and supports above the deck) shows fair condition, with minor wear flagged for upkeep.
- • The substructure (piers and abutments) rates poor at 4/9, advanced deterioration that should be prioritized for repair.
How to read this record
397TH AVE. 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 397TH AVE. against other structures in Sanborn and across South Dakota. South Dakota 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 397TH AVE.?
397TH AVE. in Sanborn, South Dakota 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 397TH AVE. inspected?
397TH AVE.'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 225 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. 397TH AVE. 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 397TH AVE.?
397TH AVE. has an NBI inventory load rating of 21.3 metric tons.
Who is responsible for maintaining 397TH AVE.?
397TH AVE. is owned and maintained by County Highway Agency.
How old is 397TH AVE. and does age affect safety?
397TH AVE. was built in 1930, making it 96 years old and last reconstructed in 1960.
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.