FHWA NBI 2024 Inspection record Public-domain dataset

FM-310TH STREET

Carrying FM-310TH STREET over IAIS RR

076412002, Pottawattamie, Iowa

Data updated May 2026

FHWA NBI record, refreshed with each annual release.

Poor
19 t Inventory load rating

Bridge Snapshot: FM-310TH STREET

The FM-310TH STREET bridge in Pottawattamie, Iowa carries FM-310TH STREET over IAIS RR. It was built in 1952, making it 74 years old today. The structure is built primarily of wood or timber and spans 7 sections, stretching 37.8 meters (124 feet) end to end. Daily traffic averages 110 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 4/9, superstructure at 6/9, substructure at 4/9. The weakest component sits in poor condition. A component scored 4 or below, placing this bridge in the federal Poor condition category rather than declaring it unsafe or closed. Its NBI inventory load rating is 19.3 metric tons.

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

How FM-310TH STREET compares

▼ 11.6
Load rating vs Iowa average (30.9 t)
Bottom 18%
Lower load rating than 82% of Iowa bridges
469
Bridges in Pottawattamie · 48 in Poor condition
FM-310TH STREET 19.3 t
Iowa average 30.9 t

Live comparison across Iowa.

Historical Sufficiency Rating

PlainBridge-computed
33.8 / 100 - historical 20–49.9 band
Structural adequacy /55
14.6
Serviceability /30
4.3
Essentiality /15
14.9
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 How the historical reference is calculated.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
4/9
Poor (1–4)
Superstructure
6/9
Fair (5–6)
Substructure
4/9
Poor (1–4)
Inventory Load Rating
19.3 t
NBI inventory level (metric tons)
Overall Condition
Poor

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

Structural Details

Year Built
1952
Material
Wood or Timber
Number of Spans
7
Structure Length
37.8 m (124 ft)
Deck Width
7.2 m (24 ft)
Owner
County Highway Agency
Avg Daily Traffic
110 vehicles/day
Structure Number
000000000288430

Condition Analysis

  • At 4/9, the deck (driving surface) is in poor shape, with advanced wear flagged for priority repair.
  • At 6/9, the superstructure (beams and supports above the deck) shows fair condition, with minor wear flagged for upkeep.
  • At 4/9, the substructure (piers and abutments) is in poor shape, with advanced wear flagged for priority repair.

How to read this record

FM-310TH STREET is in the federal Poor condition category. That is a component-based result, not a closure order.

  • NBI condition ratings reflect the latest record in this annual dataset, not a live status. Current routine inspection intervals are risk-based.
  • Understand what Poor condition does and does not mean before drawing conclusions. Poor condition explained
  • Compare FM-310TH STREET against other structures in Pottawattamie 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 FM-310TH STREET?

FM-310TH STREET in Pottawattamie, Iowa has a deck rating of 4/9, superstructure rating of 6/9, and substructure rating of 4/9 on the FHWA's 0–9 scale.

How often is FM-310TH STREET inspected?

FM-310TH STREET'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 110 vehicles per day.

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

FHWA retired that reported status beginning with the 2018 archive. FM-310TH STREET is currently shown as Poor condition from its component ratings; that category is not a live closure or safety decision.

What is the inventory load rating for FM-310TH STREET?

FM-310TH STREET has an NBI inventory load rating of 19.3 metric tons.

Who is responsible for maintaining FM-310TH STREET?

FM-310TH STREET is owned and maintained by County Highway Agency.

How old is FM-310TH STREET and does age affect safety?

FM-310TH STREET was built in 1952, making it 74 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.