L20 LOESS HILLS
Carrying L20 LOESS HILLS over WILLOW CREEK
079433016, Harrison, Iowa
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
L20 LOESS HILLS in Harrison, Iowa sits above 56% of rated Iowa bridges on inventory load rating (33 t), while its 1993 build year is earlier than 19% of Harrison's recorded-year cohort (217 bridges).
L20 LOESS HILLS in Harrison, Iowa is rated Good in the FHWA's 2024 National Bridge Inventory. Built in 1993, it carries 3 rated components on the inspecting agency's 0-9 scale, and its weakest reported component scores 7. The lowest applicable rating sets the federal condition category, so this Good result describes the weakest reported component rather than the structure as a whole. No NBI category is a closure decision or a live crossing-safety verdict.
NBI record plate
Structure IA:000000000027841
LATE-CENTURY · STEEL · MULTI-SPAN · TIED-CTRL · ARTERIAL-ADT · STANDARD-LOAD · CAT-GOOD
- LATE-CENTURY 1980–1999
- STEEL Steel
- MULTI-SPAN 3 spans
- TIED-CTRL Tied control
- ARTERIAL-ADT Arterial ADT
- STANDARD-LOAD Standard load
- CAT-GOOD Good
Inspection-sheet codes from this record’s year, material family, spans, controlling component, ADT, inventory load, and NBI category, not a live closure verdict.
Bridge Snapshot: L20 LOESS HILLS
The L20 LOESS HILLS bridge in Harrison, Iowa carries L20 LOESS HILLS over WILLOW CREEK. It was built in 1993, making it 33 years old today. The structure is built primarily of steel continuous and spans 3 sections, stretching 123.7 meters (406 feet) end to end. Daily traffic averages 1,414 vehicles, placing it in the moderately-trafficked 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 7/9, substructure at 8/9. The weakest component sits in good condition. All reported major components score above the Poor range.
How L20 LOESS HILLS compares
Age against the county: built in 1993, earlier than 41 of Harrison's 217 bridges with a recorded construction year (19%), against a county median build year of 1967. This is one of the newer structures in its county.
Live comparison across Iowa bridges with a recorded inventory load rating (23,718 of 23,719 rated).
L20 LOESS HILLS vs every rated Iowa bridge
Inventory load rating (metric tons), FHWA NBI, this state
33 Top 44% higher than 56% of 23,718 bridges
rated Iowa bridges, bucketed by value
Each bar is a band; taller bars hold more bridges. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source FHWA National Bridge Inventory · August 2026
Condition Ratings
Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.
Reported 0–9 component ratings from the FHWA NBI. The highlighted component is the lowest reported input to this record’s current condition category; it is not a closure or live crossing-safety decision.
Harrison inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 217 bridges in this county. Orthogonal to this structure's component profile above: a county catalog share, not a live crossing-safety verdict.
Structural Details
- Year Built
- 1993
- Material
- Steel Continuous
- Number of Spans
- 3
- Structure Length
- 123.7 m (406 ft)
- Deck Width
- 11.9 m (39 ft)
- Owner
- County Highway Agency
- Avg Daily Traffic
- 1,414 vehicles/day
- Structure Number
- 000000000027841
Condition Analysis
- • The deck (driving surface) rates good at 7/9, with no significant deterioration on file.
- • At 7/9, the superstructure (beams and supports above the deck) is in good shape and shows no significant wear.
- • At 8/9, the substructure (piers and abutments) is in good shape and shows no significant wear.
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 L20 LOESS HILLS 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 L20 LOESS HILLS against other structures in Harrison 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 L20 LOESS HILLS?
L20 LOESS HILLS in Harrison, Iowa has a deck rating of 7/9, superstructure rating of 7/9, and substructure rating of 8/9 on the FHWA's 0–9 scale.
How often is L20 LOESS HILLS inspected?
L20 LOESS HILLS'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 1,414 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. L20 LOESS HILLS is currently shown as Good condition from its component ratings; that category is not a live closure or safety decision.
What is the inventory load rating for L20 LOESS HILLS?
L20 LOESS HILLS has an NBI inventory load rating of 32.7 metric tons.
Who is responsible for maintaining L20 LOESS HILLS?
L20 LOESS HILLS is owned and maintained by County Highway Agency.
How old is L20 LOESS HILLS and does age affect safety?
L20 LOESS HILLS was built in 1993, making it 33 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.
Share this inspection record
Send this source-bounded record or download its data card. An NBI condition category is not a closure or live crossing-safety verdict.
Every figure on PlainBridges is rendered directly from federal source data, no number is typed in by an editor. Component ratings, ADT, and condition category on this page are copied from the NBI record for this structure; no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2024 NBI release. NBI condition categories reflect the latest reported inventory record, not a live safety, closure, or travel decision.