FHWA NBI 2024 Inspection record Public-domain dataset

390TH ST

Carrying 390TH ST over OVERFLOW LITTLE SIOUX R

095360201, Clay, Iowa

Data updated May 2026

FHWA NBI record, refreshed with each annual release.

Fair
23 t Inventory load rating

Bridge Snapshot: 390TH ST

The 390TH ST bridge in Clay, Iowa carries 390TH ST over OVERFLOW LITTLE SIOUX R. It was built in 1955, making it 71 years old today. The structure is built primarily of steel continuous and spans 3 sections, stretching 39.0 meters (128 feet) end to end. Daily traffic averages 40 vehicles, placing it in the lower-traffic tier of Iowa bridges. It is owned and maintained by County Highway Agency.

The latest FHWA inspection records show a deck rating of 5/9, superstructure at 5/9, substructure at 5/9. 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 22.7 metric tons.

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

How 390TH ST compares

▼ 8.2
Load rating vs Iowa average (30.9 t)
Bottom 27%
Lower load rating than 73% of Iowa bridges
138
Bridges in Clay · 14 in Poor condition
390TH ST 22.7 t
Iowa average 30.9 t

Live comparison across Iowa.

Historical Sufficiency Rating

PlainBridge-computed
69.1 / 100 - historical 50–79.9 band
Structural adequacy /55
35.2
Serviceability /30
22.0
Essentiality /15
15.0
Special reductions
−3.0

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 How the historical reference is calculated.

Condition Ratings

Deck
5/9
Fair (5–6)
Superstructure
5/9
Fair (5–6)
Substructure
5/9
Fair (5–6)
Inventory Load Rating
22.7 t
NBI inventory level (metric tons)
Overall Condition
Fair

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

Structural Details

Year Built
1955
Material
Steel Continuous
Number of Spans
3
Structure Length
39.0 m (128 ft)
Deck Width
6.8 m (22 ft)
Owner
County Highway Agency
Avg Daily Traffic
40 vehicles/day
Structure Number
000000000116160

Condition Analysis

  • The deck (driving surface) rates fair at 5/9, minor deterioration that routine maintenance should address.
  • At 5/9, the superstructure (beams and supports above the deck) shows fair condition, with minor wear flagged for upkeep.
  • The substructure (piers and abutments) rates fair at 5/9, minor deterioration that routine maintenance should address.

How to read this record

This page shows what the last federal inspection recorded, not whether 390TH ST 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 390TH ST against other structures in Clay 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 390TH ST?

390TH ST in Clay, Iowa has a deck rating of 5/9, superstructure rating of 5/9, and substructure rating of 5/9 on the FHWA's 0–9 scale.

How often is 390TH ST inspected?

390TH 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 40 vehicles per day.

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

FHWA retired that reported status beginning with the 2018 archive. 390TH ST 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 390TH ST?

390TH ST has an NBI inventory load rating of 22.7 metric tons.

Who is responsible for maintaining 390TH ST?

390TH ST is owned and maintained by County Highway Agency.

How old is 390TH ST and does age affect safety?

390TH ST was built in 1955, making it 71 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.