478TH AVENUE
Carrying 478TH AVENUE over DEER CK
2.7N BUSHNELL, Brookings, South Dakota
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: 478TH AVENUE
The 478TH AVENUE bridge in Brookings, South Dakota carries 478TH AVENUE over DEER CK. It was built in 1950, making it 76 years old today. The structure is built primarily of steel and spans 1 section, stretching 9.1 meters (30 feet) end to end. Daily traffic averages 712 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 3/9, superstructure at 4/9, substructure at 4/9. The weakest component sits in poor condition. Because at least one major component scores 4 or lower, this bridge falls in FHWA's Poor condition category. That category is not a closure order. Its NBI inventory load rating is 21.0 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How 478TH AVENUE 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 How the historical reference is calculated.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
- 1950
- Material
- Steel
- Number of Spans
- 1
- Structure Length
- 9.1 m (30 ft)
- Deck Width
- 7.3 m (24 ft)
- Owner
- County Highway Agency
- Avg Daily Traffic
- 712 vehicles/day
- Structure Number
- 000000006240123
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗Condition Analysis
- • The deck (driving surface) rates poor at 3/9, advanced deterioration that should be prioritized for repair.
- • The superstructure (beams and supports above the deck) is in poor condition (4/9), showing advanced deterioration that may require 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
478TH AVENUE 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 478TH AVENUE against other structures in Brookings 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 AVENUE?
478TH AVENUE in Brookings, South Dakota has a deck rating of 3/9, superstructure rating of 4/9, and substructure rating of 4/9 on the FHWA's 0–9 scale.
How often is 478TH AVENUE inspected?
478TH AVENUE'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 712 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. 478TH AVENUE 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 478TH AVENUE?
478TH AVENUE has an NBI inventory load rating of 21.0 metric tons.
Who is responsible for maintaining 478TH AVENUE?
478TH AVENUE is owned and maintained by County Highway Agency.
How old is 478TH AVENUE and does age affect safety?
478TH AVENUE was built in 1950, making it 76 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.