20th ST S
Carrying 20th ST S over I029
2 S US 14 INTCH, Brookings, South Dakota
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
20th ST S in Brookings, South Dakota sits above 80% of rated South Dakota bridges on inventory load rating (42 t), while its 2022 build year is earlier than 0% of Brookings's recorded-year cohort (233 bridges).
20th ST S in Brookings, South Dakota is rated Good in the FHWA's 2024 National Bridge Inventory. Built in 2022, it carries 3 rated components on the inspecting agency's 0-9 scale, and its weakest reported component scores 7. The lowest applicable rating sets the federal condition category, so this Good result describes the weakest reported component rather than the structure as a whole. No NBI category is a closure decision or a live crossing-safety verdict.
NBI record plate
Structure SD:000000006185180
POST-2000 · PRESTRESS · MULTI-SPAN · DECK-LED · ARTERIAL-ADT · HEAVY-LOAD · CAT-GOOD
- POST-2000 2000+
- PRESTRESS Prestressed concrete
- MULTI-SPAN 2 spans
- DECK-LED Deck-led
- ARTERIAL-ADT Arterial ADT
- HEAVY-LOAD Heavy load
- CAT-GOOD Good
Inspection-sheet codes from this record’s year, material family, spans, controlling component, ADT, inventory load, and NBI category, not a live closure verdict.
Bridge Snapshot: 20th ST S
The 20th ST S bridge in Brookings, South Dakota carries 20th ST S over I029. It was built in 2022, making it 4 years old today. The structure is built primarily of prestressed concrete and spans 2 sections, stretching 79.3 meters (260 feet) end to end. Daily traffic averages 2,500 vehicles, placing it in the moderately-trafficked tier of South Dakota bridges. It is owned and maintained by State Highway Agency.
The latest FHWA inspection records show a deck rating of 7/9, superstructure at 8/9, substructure at 8/9. The weakest component sits in good condition. No reported major component scores in the Poor range under the current federal condition thresholds.
How 20th ST S compares
Age against the county: built in 2022, earlier than 1 of Brookings's 233 bridges with a recorded construction year (0%), against a county median build year of 1970. This is one of the newer structures in its county.
Live comparison across South Dakota bridges with a recorded inventory load rating (5,886 of 5,887 rated).
20th ST S vs every rated South Dakota bridge
Inventory load rating (metric tons), FHWA NBI, this state
42 Top 20% higher than 80% of 5,886 bridges
rated South Dakota bridges, bucketed by value
Each bar is a band; taller bars hold more bridges. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source FHWA National Bridge Inventory · August 2026
Condition Ratings
Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.
Reported 0–9 component ratings from the FHWA NBI. The highlighted component is the lowest reported input to this record’s current condition category; it is not a closure or live crossing-safety decision.
Brookings inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 233 bridges in this county. Orthogonal to this structure's component profile above: a county catalog share, not a live crossing-safety verdict.
Structural Details
- Year Built
- 2022
- Material
- Prestressed Concrete
- Number of Spans
- 2
- Structure Length
- 79.3 m (260 ft)
- Deck Width
- 17.6 m (58 ft)
- Owner
- State Highway Agency
- Avg Daily Traffic
- 2,500 vehicles/day
- Structure Number
- 000000006185180
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 8/9, with no significant deterioration on file.
- • At 8/9, the substructure (piers and abutments) is in good shape and shows no significant wear.
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 20th ST S 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 20th ST S 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 20th ST S?
20th ST S in Brookings, South Dakota has a deck rating of 7/9, superstructure rating of 8/9, and substructure rating of 8/9 on the FHWA's 0–9 scale.
How often is 20th ST S inspected?
20th ST S'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 2,500 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. 20th ST S 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 20th ST S?
20th ST S has an NBI inventory load rating of 42.0 metric tons.
Who is responsible for maintaining 20th ST S?
20th ST S is owned and maintained by State Highway Agency.
How old is 20th ST S and does age affect safety?
20th ST S was built in 2022, making it 4 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.
Share this inspection record
Send this source-bounded record or download its data card. An NBI condition category is not a closure or live crossing-safety verdict.
Every figure on PlainBridges is rendered directly from federal source data, no number is typed in by an editor. Component ratings, ADT, and condition category on this page are copied from the NBI record for this structure; no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2024 NBI release. NBI condition categories reflect the latest reported inventory record, not a live safety, closure, or travel decision.