FHWA NBI 2024 Inspection record Public-domain dataset

US 34

Carrying US 34 over TWELVE MILE CREEK

2.4 MI. W OF JCT. U.S.169, Union, Iowa

Data updated May 2026

FHWA NBI record, refreshed with each annual release.

Fair
28 t Inventory load rating

Bridge Snapshot: US 34

The US 34 bridge in Union, Iowa carries US 34 over TWELVE MILE CREEK. It was built in 1971, making it 55 years old today. The structure is built primarily of concrete continuous and spans 2 sections, stretching 6.4 meters (21 feet) end to end. Daily traffic averages 4,890 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 culvert at 6/9. The weakest component sits in fair condition. No reported major component scores in the Poor range under the current federal condition thresholds. Its NBI inventory load rating is 27.9 metric tons.

Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.

How US 34 compares

▼ 3.0
Load rating vs Iowa average (30.9 t)
Bottom 40%
Lower load rating than 60% of Iowa bridges
153
Bridges in Union · 54 in Poor condition
US 34 27.9 t
Iowa average 30.9 t

Live comparison across Iowa.

Historical Sufficiency Rating

PlainBridge-computed
85.7 / 100 - historical 80–100 band
Structural adequacy /55
51.9
Serviceability /30
30.0
Essentiality /15
3.8
Special reductions
0

FHWA discontinued this calculated item; it does not determine current condition, funding eligibility, posting, or closure. How the historical reference is calculated.

Condition Ratings

Culvert
6/9
Fair (5–6)
Inventory Load Rating
27.9 t
NBI inventory level (metric tons)
Overall Condition
Fair

Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.

Structural Details

Year Built
1971
Material
Concrete Continuous
Number of Spans
2
Structure Length
6.4 m (21 ft)
Owner
State Highway Agency
Avg Daily Traffic
4,890 vehicles/day
Structure Number
000000000050051

How to read this record

This page shows what the last federal inspection recorded, not whether US 34 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 US 34 against other structures in Union 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 US 34?

US 34 in Union, Iowa on the FHWA's 0–9 scale.

How often is US 34 inspected?

US 34'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 4,890 vehicles per day.

What does “structurally deficient” mean in older bridge reports?

FHWA retired that reported status beginning with the 2018 archive. US 34 is currently shown as Fair condition from its component ratings; that category is not a live closure or safety decision.

What is the inventory load rating for US 34?

US 34 has an NBI inventory load rating of 27.9 metric tons.

Who is responsible for maintaining US 34?

US 34 is owned and maintained by State Highway Agency.

How old is US 34 and does age affect safety?

US 34 was built in 1971, making it 55 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.

Data sourced from the Federal Highway Administration National Bridge Inventory. See our methodology for details. Retrieved and formatted by PlainBridges

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.