FHWA NBI 2024 Inspection record Public-domain dataset

450TH

Carrying 450TH over LITTLE CEDAR RIVER

099160803, Mitchell, Iowa

Data updated May 2026

FHWA NBI record, refreshed with each annual release.

Fair
36 t Inventory load rating

Bridge Snapshot: 450TH

The 450TH bridge in Mitchell, Iowa carries 450TH over LITTLE CEDAR RIVER. It was built in 1992, making it 34 years old today. The structure is built primarily of prestressed concrete and spans 3 sections, stretching 46.9 meters (154 feet) end to end. Daily traffic averages 78 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 7/9, superstructure at 6/9, substructure at 7/9. The weakest component sits in fair condition. All reported major components score above the Poor range. Its NBI inventory load rating is 36.3 metric tons.

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

How 450TH compares

▲ 5.4
Load rating vs Iowa average (30.9 t)
Top 25%
Higher load rating than 75% of Iowa bridges
160
Bridges in Mitchell · 15 in Poor condition
450TH 36.3 t
Iowa average 30.9 t

Live comparison across Iowa.

Historical Sufficiency Rating

PlainBridge-computed
100.0 / 100 - historical 80–100 band
Structural adequacy /55
55.0
Serviceability /30
30.0
Essentiality /15
15.0
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 How the historical reference is calculated.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

Deck
7/9
Good (7–9)
Superstructure
6/9
Fair (5–6)
Substructure
7/9
Good (7–9)
Inventory Load Rating
36.3 t
NBI inventory level (metric tons)
Overall Condition
Fair

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

Structural Details

Year Built
1992
Material
Prestressed Concrete
Number of Spans
3
Structure Length
46.9 m (154 ft)
Deck Width
10.1 m (33 ft)
Owner
County Highway Agency
Avg Daily Traffic
78 vehicles/day
Structure Number
000000000248421

Condition Analysis

  • The deck (driving surface) rates good at 7/9, with no significant deterioration on file.
  • At 6/9, the superstructure (beams and supports above the deck) shows fair condition, with minor wear flagged for upkeep.
  • The substructure (piers and abutments) rates good at 7/9, with no significant deterioration on file.

How to read this record

This page shows what the last federal inspection recorded, not whether 450TH 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 450TH against other structures in Mitchell 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 450TH?

450TH in Mitchell, Iowa has a deck rating of 7/9, superstructure rating of 6/9, and substructure rating of 7/9 on the FHWA's 0–9 scale.

How often is 450TH inspected?

450TH'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 78 vehicles per day.

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

FHWA retired that reported status beginning with the 2018 archive. 450TH 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 450TH?

450TH has an NBI inventory load rating of 36.3 metric tons.

Who is responsible for maintaining 450TH?

450TH is owned and maintained by County Highway Agency.

How old is 450TH and does age affect safety?

450TH was built in 1992, making it 34 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.