FHWA NBI 2024 Inspection record Public-domain dataset

ISLAND BROOK AVE

Carrying ISLAND BROOK AVE over PEQUONNOCK RIVER

0.4 MI E OF US ROUTE 1, Unknown County, Connecticut

Inventory: FHWA NBI 2024 · last ETL August 2026

FHWA NBI record, refreshed with each annual release.

Poor
27 t Inventory load rating Lower than 91% of rated Connecticut bridges

ISLAND BROOK AVE in Unknown County, Connecticut sits above 9% of rated Connecticut bridges on inventory load rating (27 t), while its 1938 build year is earlier than 84% of Unknown County's recorded-year cohort (861 bridges).

ISLAND BROOK AVE in Unknown County, Connecticut is rated Poor in the FHWA's 2024 National Bridge Inventory. Built in 1938, it carries 3 rated components on the inspecting agency's 0-9 scale, and its weakest reported component scores 4. The lowest applicable rating sets the federal condition category, so this Poor 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 CT:04227

PRE-1950 · CONCRETE · SINGLE-SPAN · DECK-LED · ARTERIAL-ADT · STANDARD-LOAD · CAT-POOR

  • PRE-1950 Pre-1950
  • CONCRETE Concrete
  • SINGLE-SPAN Single span
  • DECK-LED Deck-led
  • ARTERIAL-ADT Arterial ADT
  • STANDARD-LOAD Standard load
  • CAT-POOR Poor

Inspection-sheet codes from this record’s year, material family, spans, controlling component, ADT, inventory load, and NBI category, not a live closure verdict.

Structural health score

A composite of the deck, superstructure, and substructure NBI condition ratings plus the inventory load rating, benchmarked against the full national bridge corpus, distinct from the Good/Fair/Poor category above.

F
Overall Score
15/100
ISLAND BROOK AVE
Deck Condition F
4/9
NBI deck condition rating (0=failed, 9=excellent)
Superstructure Condition F
5/9
NBI superstructure condition rating (0=failed, 9=excellent)
Substructure Condition F
5/9
NBI substructure condition rating (0=failed, 9=excellent)
Load Rating F
27 t
NBI inventory load rating vs the national corpus

Bridge Snapshot: ISLAND BROOK AVE

The ISLAND BROOK AVE bridge in Unknown County, Connecticut carries ISLAND BROOK AVE over PEQUONNOCK RIVER. It was built in 1938, making it 88 years old today. The structure is built primarily of concrete and spans 1 section, stretching 16.5 meters (54 feet) end to end. Daily traffic averages 8,240 vehicles, placing it in the moderately-trafficked tier of Connecticut bridges. It is owned and maintained by City/Municipal Highway Agency.

The latest FHWA inspection places the weakest component in poor condition (see the full component ratings below). Because at least one major component scores 4 or lower, this bridge falls in FHWA's Poor condition category. That category is not a closure order.

How ISLAND BROOK AVE compares

▼ 16.9
Load rating vs Connecticut average (44.1 t; 4,365 rated)
861
Bridges in Unknown County · 35 in Poor condition

Age against the county: built in 1938, earlier than 720 of Unknown County's 861 bridges with a recorded construction year (84%), against a county median build year of 1962. Age is not a defect on its own, but it is the population from which future Poor ratings are drawn.

ISLAND BROOK AVE 27.2 t
Connecticut average (4,365 rated) 44.1 t

Live comparison across Connecticut bridges with a recorded inventory load rating (4,365 rated).

ISLAND BROOK AVE vs every rated Connecticut bridge

Inventory load rating (metric tons), FHWA NBI, this state

27 Top 91% higher than 9% of 4,365 bridges

rated Connecticut 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

Deck
4/9
Poor (1–4)
Superstructure
5/9
Fair (5–6)
Substructure
5/9
Fair (5–6)
Inventory Load Rating
27.2 t
NBI inventory level (metric tons)
Overall Condition
Poor

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.

Unknown County inventory by recorded NBI category

Exclusive Good/Fair/Poor bands across all 861 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
1938
Material
Concrete
Number of Spans
1
Structure Length
16.5 m (54 ft)
Deck Width
16.1 m (53 ft)
Owner
City/Municipal Highway Agency
Avg Daily Traffic
8,240 vehicles/day
Structure Number
04227

Condition Analysis

  • • At 4/9, the deck (driving surface) is in poor shape, with advanced wear on file for this vintage.
  • • The superstructure (beams and supports above the deck) is in fair condition (5/9), with minor deterioration that may require routine maintenance.
  • • At 5/9, the substructure (piers and abutments) shows fair condition, with minor wear flagged for upkeep.

How to read this record

ISLAND BROOK AVE 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 ISLAND BROOK AVE against other structures in Unknown County and across Connecticut. Connecticut 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 ISLAND BROOK AVE?

ISLAND BROOK AVE in Unknown County, Connecticut has a deck rating of 4/9, superstructure rating of 5/9, and substructure rating of 5/9 on the FHWA's 0–9 scale.

How often is ISLAND BROOK AVE inspected?

ISLAND BROOK 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 8,240 vehicles per day.

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

FHWA retired that reported status beginning with the 2018 archive. ISLAND BROOK AVE 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 ISLAND BROOK AVE?

ISLAND BROOK AVE has an NBI inventory load rating of 27.2 metric tons.

Who is responsible for maintaining ISLAND BROOK AVE?

ISLAND BROOK AVE is owned and maintained by City/Municipal Highway Agency.

How old is ISLAND BROOK AVE and does age affect safety?

ISLAND BROOK AVE was built in 1938, making it 88 years old.

Data sourced from the Federal Highway Administration National Bridge Inventory. See our methodology for details.

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.

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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.