156TH ST NB
Carrying 156TH ST NB over WALNUT CREEK
200 ft North of Brookview, Dallas, Iowa
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
156TH ST NB in Dallas, Iowa sits above 51% of rated Iowa bridges on inventory load rating (32 t), while its 2015 build year is earlier than 9% of Dallas's recorded-year cohort (199 bridges).
156TH ST NB in Dallas, Iowa is rated Good in the FHWA's 2024 National Bridge Inventory. Built in 2015, it carries 3 rated components on the inspecting agency's 0-9 scale, and its weakest reported component scores 8. 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:000000000505340
POST-2000 · CONCRETE · MULTI-SPAN · TIED-CTRL · LOCAL-ADT · STANDARD-LOAD · CAT-GOOD
- POST-2000 2000+
- CONCRETE Concrete
- MULTI-SPAN 3 spans
- TIED-CTRL Tied control
- LOCAL-ADT Local 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: 156TH ST NB
The 156TH ST NB bridge in Dallas, Iowa carries 156TH ST NB over WALNUT CREEK. It was built in 2015, making it 11 years old today. The structure is built primarily of concrete continuous and spans 3 sections, stretching 52.1 meters (171 feet) end to end. Daily traffic averages 222 vehicles, placing it in the lower-traffic tier of Iowa bridges. It is owned and maintained by City/Municipal Highway Agency.
The latest FHWA inspection records show a deck rating of 8/9, superstructure at 8/9, substructure at 8/9. The weakest component sits in good condition. All reported major components score above the Poor range.
How 156TH ST NB compares
Age against the county: built in 2015, earlier than 18 of Dallas's 199 bridges with a recorded construction year (9%), against a county median build year of 1979. This is one of the newer structures in its county.
Live comparison across Iowa bridges with a recorded inventory load rating (23,718 of 23,719 rated).
156TH ST NB vs every rated Iowa bridge
Inventory load rating (metric tons), FHWA NBI, this state
32 Top 49% higher than 51% 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.
Dallas inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 199 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
- 2015
- Material
- Concrete Continuous
- Number of Spans
- 3
- Structure Length
- 52.1 m (171 ft)
- Deck Width
- 11.9 m (39 ft)
- Owner
- City/Municipal Highway Agency
- Avg Daily Traffic
- 222 vehicles/day
- Structure Number
- 000000000505340
Condition Analysis
- • The deck (driving surface) is in good condition (8/9), showing no significant deterioration.
- • The superstructure (beams and supports above the deck) rates good at 8/9, with no significant deterioration on file.
- • The substructure (piers and abutments) rates good at 8/9, 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 156TH ST NB 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 156TH ST NB against other structures in Dallas 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 156TH ST NB?
156TH ST NB in Dallas, Iowa has a deck rating of 8/9, superstructure rating of 8/9, and substructure rating of 8/9 on the FHWA's 0–9 scale.
How often is 156TH ST NB inspected?
156TH ST NB'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 222 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. 156TH ST NB 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 156TH ST NB?
156TH ST NB has an NBI inventory load rating of 32.4 metric tons.
Who is responsible for maintaining 156TH ST NB?
156TH ST NB is owned and maintained by City/Municipal Highway Agency.
How old is 156TH ST NB and does age affect safety?
156TH ST NB was built in 2015, making it 11 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.