FHWA NBI 2024 Inspection record Public-domain dataset

BACKBONE STATE PK

Carrying BACKBONE STATE PK over BR MAQUOKETA RIVER

IN BACKBONE STATE PARK, Delaware, Iowa

Data updated May 2026

FHWA NBI record, refreshed with each annual release.

Fair
34 t Inventory load rating

Bridge Snapshot: BACKBONE STATE PK

The BACKBONE STATE PK bridge in Delaware, Iowa carries BACKBONE STATE PK over BR MAQUOKETA RIVER. It was built in 1976, making it 50 years old today. The structure is built primarily of concrete continuous and spans 4 sections, stretching 42.4 meters (139 feet) end to end. Average daily traffic is not reported for this structure. It is owned and maintained by State Park/Forest/Reservation.

The latest FHWA inspection records show a deck rating of 6/9, 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 33.5 metric tons.

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

How BACKBONE STATE PK compares

▲ 2.6
Load rating vs Iowa average (30.9 t)
Top 32%
Higher load rating than 68% of Iowa bridges
254
Bridges in Delaware · 17 in Poor condition
BACKBONE STATE PK 33.5 t
Iowa average 30.9 t

Live comparison across Iowa.

Historical Sufficiency Rating

PlainBridge-computed
93.0 / 100 - historical 80–100 band
Structural adequacy /55
55.0
Serviceability /30
28.0
Essentiality /15
15.0
Special reductions
−5.0

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 How the historical reference is calculated.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
7/9
Good (7–9)
Inventory Load Rating
33.5 t
NBI inventory level (metric tons)
Overall Condition
Fair

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

Structural Details

Year Built
1976
Material
Concrete Continuous
Number of Spans
4
Structure Length
42.4 m (139 ft)
Deck Width
9.8 m (32 ft)
Owner
State Park/Forest/Reservation
Structure Number
000000000699055

Condition Analysis

  • At 6/9, the deck (driving surface) shows fair condition, with minor wear flagged for upkeep.
  • The superstructure (beams and supports above the deck) is in fair condition (6/9), with minor deterioration that may require routine maintenance.
  • At 7/9, the substructure (piers and abutments) is in good shape and shows no significant wear.

How to read this record

This page shows what the last federal inspection recorded, not whether BACKBONE STATE PK 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 BACKBONE STATE PK against other structures in Delaware 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 BACKBONE STATE PK?

BACKBONE STATE PK in Delaware, Iowa has a deck rating of 6/9, superstructure rating of 6/9, and substructure rating of 7/9 on the FHWA's 0–9 scale.

How often is BACKBONE STATE PK inspected?

BACKBONE STATE PK's responsible agency sets its routine interval under FHWA's risk-based inspection rules; this page does not expose the scheduled interval.

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

FHWA retired that reported status beginning with the 2018 archive. BACKBONE STATE PK 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 BACKBONE STATE PK?

BACKBONE STATE PK has an NBI inventory load rating of 33.5 metric tons.

Who is responsible for maintaining BACKBONE STATE PK?

BACKBONE STATE PK is owned and maintained by State Park/Forest/Reservation.

How old is BACKBONE STATE PK and does age affect safety?

BACKBONE STATE PK was built in 1976, making it 50 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.