SE 6TH ST
Carrying SE 6TH ST over DES MOINES RIVER
000000000, Polk, Iowa
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
SE 6TH ST in Polk, Iowa sits above 34% of rated Iowa bridges on inventory load rating (25 t), while its 1976 build year is earlier than 68% of Polk's recorded-year cohort (545 bridges).
SE 6TH ST in Polk, Iowa is rated Poor in the FHWA's 2024 National Bridge Inventory. Built in 1976, it carries 3 rated components on the inspecting agency's 0-9 scale, and its weakest reported component scores 4. The lowest applicable rating sets the federal condition category, so this Poor 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:000000000004090
INTERSTATE-ERA · STEEL · LONG-SPAN-RUN · SUPER-LED · ARTERIAL-ADT · STANDARD-LOAD · CAT-POOR
- INTERSTATE-ERA 1950–1979
- STEEL Steel
- LONG-SPAN-RUN 7 spans
- SUPER-LED Superstructure-led
- ARTERIAL-ADT Arterial ADT
- STANDARD-LOAD Standard load
- CAT-POOR Poor
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: SE 6TH ST
The SE 6TH ST bridge in Polk, Iowa carries SE 6TH ST over DES MOINES RIVER. It was built in 1976, making it 50 years old today. It was last reconstructed in 2010, extending its service life. The structure is built primarily of steel continuous and spans 7 sections, stretching 253.0 meters (830 feet) end to end. Daily traffic averages 7,911 vehicles, placing it in the moderately-trafficked tier of Iowa bridges. It is owned and maintained by City/Municipal Highway Agency.
The latest FHWA inspection records show a deck rating of 5/9, superstructure at 4/9, substructure at 5/9. 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.
How SE 6TH ST compares
Age against the county: built in 1976, earlier than 370 of Polk's 545 bridges with a recorded construction year (68%), against a county median build year of 1994. 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).
SE 6TH ST vs every rated Iowa bridge
Inventory load rating (metric tons), FHWA NBI, this state
25 Top 66% higher than 34% 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.
Polk inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 545 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
- 1976
- Last Reconstructed
- 2010
- Material
- Steel Continuous
- Number of Spans
- 7
- Structure Length
- 253.0 m (830 ft)
- Deck Width
- 19.9 m (65 ft)
- Owner
- City/Municipal Highway Agency
- Avg Daily Traffic
- 7,911 vehicles/day
- Structure Number
- 000000000004090
Condition Analysis
- • The deck (driving surface) rates fair at 5/9, minor deterioration that routine maintenance should address.
- • At 4/9, the superstructure (beams and supports above the deck) is in poor shape, with advanced wear on file for this vintage.
- • The substructure (piers and abutments) is in fair condition (5/9), with minor deterioration that may require routine maintenance.
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗How to read this record
SE 6TH ST 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 SE 6TH ST against other structures in Polk 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 SE 6TH ST?
SE 6TH ST in Polk, Iowa has a deck rating of 5/9, superstructure rating of 4/9, and substructure rating of 5/9 on the FHWA's 0–9 scale.
How often is SE 6TH ST inspected?
SE 6TH ST'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 7,911 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. SE 6TH ST 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 SE 6TH ST?
SE 6TH ST has an NBI inventory load rating of 25.4 metric tons.
Who is responsible for maintaining SE 6TH ST?
SE 6TH ST is owned and maintained by City/Municipal Highway Agency.
How old is SE 6TH ST and does age affect safety?
SE 6TH ST was built in 1976, making it 50 years old and last reconstructed in 2010.
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.