S 18TH AVE
Carrying S 18TH AVE over US 30
1.5 MILES E OF JCT IA 14, Marshall, Iowa
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: S 18TH AVE
The S 18TH AVE bridge in Marshall, Iowa carries S 18TH AVE over US 30. It was built in 1995, making it 31 years old today. The structure is built primarily of prestressed concrete. Daily traffic averages 10,500 vehicles, placing it in the heavily-trafficked tier of Iowa bridges.
The latest FHWA inspection records show limited component ratings on file. The weakest component sits in unrated condition. All reported major components score above the Poor range.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How S 18TH AVE compares
Live comparison across Iowa.
Historical Sufficiency Rating
PlainBridge-computedFHWA discontinued this calculated item; it does not determine current condition, funding eligibility, posting, or closure. How the historical reference is calculated.
Condition Ratings
Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.
Structural Details
- Year Built
- 1995
- Material
- Prestressed Concrete
- Avg Daily Traffic
- 10,500 vehicles/day
- Structure Number
- 000000000601910
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 S 18TH AVE 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 S 18TH AVE against other structures in Marshall 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 S 18TH AVE?
S 18TH AVE in Marshall, Iowa on the FHWA's 0–9 scale.
How often is S 18TH AVE inspected?
S 18TH AVE'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 10,500 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. S 18TH AVE is currently shown as unrated condition from its component ratings; that category is not a live closure or safety decision.
What is the inventory load rating for S 18TH AVE?
An inventory load rating is not recorded for S 18TH AVE.
Who is responsible for maintaining S 18TH AVE?
Ownership is not specified for S 18TH AVE in the NBI.
How old is S 18TH AVE and does age affect safety?
S 18TH AVE was built in 1995, making it 31 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.
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.