478TH AVE, HWY 121
Carrying 478TH AVE, HWY 121 over SLIP-UP CREEK
4E & 1.3S BALTIC, Minnehaha, South Dakota
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: 478TH AVE, HWY 121
The 478TH AVE, HWY 121 bridge in Minnehaha, South Dakota carries 478TH AVE, HWY 121 over SLIP-UP CREEK. It was built in 2013, making it 13 years old today. The structure is built primarily of concrete continuous and spans 4 sections, stretching 16.5 meters (54 feet) end to end. Daily traffic averages 1,152 vehicles, placing it in the moderately-trafficked tier of South Dakota bridges. It is owned and maintained by County Highway Agency.
The latest FHWA inspection records show culvert at 7/9. The weakest component sits in good condition. All reported major components score above the Poor range. Its NBI inventory load rating is 27.0 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How 478TH AVE, HWY 121 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 How the historical reference is calculated.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
- 2013
- Material
- Concrete Continuous
- Number of Spans
- 4
- Structure Length
- 16.5 m (54 ft)
- Owner
- County Highway Agency
- Avg Daily Traffic
- 1,152 vehicles/day
- Structure Number
- 000000050240073
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗How to read this record
This page shows what the last federal inspection recorded, not whether 478TH AVE, HWY 121 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 478TH AVE, HWY 121 against other structures in Minnehaha 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 478TH AVE, HWY 121?
478TH AVE, HWY 121 in Minnehaha, South Dakota on the FHWA's 0–9 scale.
How often is 478TH AVE, HWY 121 inspected?
478TH AVE, HWY 121'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 1,152 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. 478TH AVE, HWY 121 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 478TH AVE, HWY 121?
478TH AVE, HWY 121 has an NBI inventory load rating of 27.0 metric tons.
Who is responsible for maintaining 478TH AVE, HWY 121?
478TH AVE, HWY 121 is owned and maintained by County Highway Agency.
How old is 478TH AVE, HWY 121 and does age affect safety?
478TH AVE, HWY 121 was built in 2013, making it 13 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.