FHWA NBI 2024 Inspection record Public-domain dataset

US 18

Carrying US 18 over BEAVER CREEK

3.7 MI. W OF SR V14, Chickasaw, Iowa

Data updated May 2026

FHWA NBI record, refreshed with each annual release.

Fair
36 t Inventory load rating

Bridge Snapshot: US 18

The US 18 bridge in Chickasaw, Iowa carries US 18 over BEAVER CREEK. It was built in 1978, making it 48 years old today. The structure is built primarily of concrete continuous and spans 3 sections, stretching 37.5 meters (123 feet) end to end. Daily traffic averages 2,120 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 a deck rating of 6/9, superstructure at 6/9, substructure at 6/9. 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 US 18 compares

▲ 5.4
Load rating vs Iowa average (30.9 t)
Top 25%
Higher load rating than 75% of Iowa bridges
268
Bridges in Chickasaw · 73 in Poor condition
US 18 36.3 t
Iowa average 30.9 t

Live comparison across Iowa.

Historical Sufficiency Rating

PlainBridge-computed
98.4 / 100 - historical 80–100 band
Structural adequacy /55
55.0
Serviceability /30
30.0
Essentiality /15
13.4
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 How the historical reference is calculated.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
6/9
Fair (5–6)
Superstructure
6/9
Fair (5–6)
Substructure
6/9
Fair (5–6)
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
1978
Material
Concrete Continuous
Number of Spans
3
Structure Length
37.5 m (123 ft)
Deck Width
14.4 m (47 ft)
Owner
State Highway Agency
Avg Daily Traffic
2,120 vehicles/day
Structure Number
000000000019591

Condition Analysis

  • The deck (driving surface) is in fair condition (6/9), with minor deterioration that may require routine maintenance.
  • The superstructure (beams and supports above the deck) is in fair condition (6/9), with minor deterioration that may require routine maintenance.
  • The substructure (piers and abutments) is in fair condition (6/9), with minor deterioration that may require routine maintenance.

How to read this record

This page shows what the last federal inspection recorded, not whether US 18 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 18 against other structures in Chickasaw 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 18?

US 18 in Chickasaw, Iowa has a deck rating of 6/9, superstructure rating of 6/9, and substructure rating of 6/9 on the FHWA's 0–9 scale.

How often is US 18 inspected?

US 18'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 2,120 vehicles per day.

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

FHWA retired that reported status beginning with the 2018 archive. US 18 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 18?

US 18 has an NBI inventory load rating of 36.3 metric tons.

Who is responsible for maintaining US 18?

US 18 is owned and maintained by State Highway Agency.

How old is US 18 and does age affect safety?

US 18 was built in 1978, making it 48 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.