Y21 SUNDOWN RD
Carrying Y21 SUNDOWN RD over US 20 US 52
AT JCT SR- Y21, Dubuque, Iowa
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
Y21 SUNDOWN RD in Dubuque, Iowa sits above 50% of rated Iowa bridges on inventory load rating (32 t), while its 1987 build year is earlier than 61% of Dubuque's recorded-year cohort (346 bridges).
Y21 SUNDOWN RD in Dubuque, Iowa is rated Good in the FHWA's 2024 National Bridge Inventory. Built in 1987, 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 IA:000000000605745
LATE-CENTURY · PRESTRESS · LONG-SPAN-RUN · TIED-CTRL · ARTERIAL-ADT · STANDARD-LOAD · CAT-GOOD
- LATE-CENTURY 1980–1999
- PRESTRESS Prestressed concrete
- LONG-SPAN-RUN 4 spans
- TIED-CTRL Tied control
- ARTERIAL-ADT Arterial ADT
- STANDARD-LOAD Standard 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: Y21 SUNDOWN RD
The Y21 SUNDOWN RD bridge in Dubuque, Iowa carries Y21 SUNDOWN RD over US 20 US 52. It was built in 1987, making it 39 years old today. The structure is built primarily of prestressed concrete and spans 4 sections, stretching 78.3 meters (257 feet) end to end. Daily traffic averages 6,285 vehicles, placing it in the moderately-trafficked tier of Iowa bridges. It is owned and maintained by State Highway Agency.
The latest FHWA inspection records show a deck rating of 7/9, superstructure at 7/9, substructure at 7/9. The weakest component sits in good condition. All reported major components score above the Poor range.
How Y21 SUNDOWN RD compares
Age against the county: built in 1987, earlier than 211 of Dubuque's 346 bridges with a recorded construction year (61%), against a county median build year of 1995. Age is not a defect on its own, but it is the population from which future Poor ratings are drawn.
Live comparison across Iowa bridges with a recorded inventory load rating (23,718 of 23,719 rated).
Y21 SUNDOWN RD vs every rated Iowa bridge
Inventory load rating (metric tons), FHWA NBI, this state
32 Top 50% higher than 50% of 23,718 bridges
rated Iowa 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.
Dubuque inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 346 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
- 1987
- Material
- Prestressed Concrete
- Number of Spans
- 4
- Structure Length
- 78.3 m (257 ft)
- Deck Width
- 13.2 m (43 ft)
- Owner
- State Highway Agency
- Avg Daily Traffic
- 6,285 vehicles/day
- Structure Number
- 000000000605745
Condition Analysis
- • The deck (driving surface) rates good at 7/9, with no significant deterioration on file.
- • The superstructure (beams and supports above the deck) rates good at 7/9, with no significant deterioration on file.
- • The substructure (piers and abutments) rates good at 7/9, with no significant deterioration on file.
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 Y21 SUNDOWN RD 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 Y21 SUNDOWN RD against other structures in Dubuque and across Iowa. Iowa 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 Y21 SUNDOWN RD?
Y21 SUNDOWN RD in Dubuque, Iowa has a deck rating of 7/9, superstructure rating of 7/9, and substructure rating of 7/9 on the FHWA's 0–9 scale.
How often is Y21 SUNDOWN RD inspected?
Y21 SUNDOWN RD'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 6,285 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. Y21 SUNDOWN RD 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 Y21 SUNDOWN RD?
Y21 SUNDOWN RD has an NBI inventory load rating of 31.9 metric tons.
Who is responsible for maintaining Y21 SUNDOWN RD?
Y21 SUNDOWN RD is owned and maintained by State Highway Agency.
How old is Y21 SUNDOWN RD and does age affect safety?
Y21 SUNDOWN RD was built in 1987, making it 39 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.