FHWA NBI 2024 Inspection record Public-domain dataset

ALGONQUIN RD

Carrying ALGONQUIN RD over SPRING CR

0.1 MI SW PLUM TREE, McHenry, Illinois

Data updated May 2026

FHWA NBI record, refreshed with each annual release.

Poor
9 t Inventory load rating

Bridge Snapshot: ALGONQUIN RD

The ALGONQUIN RD bridge in McHenry, Illinois carries ALGONQUIN RD over SPRING CR. It was built in 1986, making it 40 years old today. The structure is built primarily of prestressed concrete and spans 1 section, stretching 16.2 meters (53 feet) end to end. Daily traffic averages 3,200 vehicles, placing it in the moderately-trafficked tier of Illinois bridges. It is owned and maintained by Town/Township Highway Agency.

The latest FHWA inspection records show a deck rating of 3/9, superstructure at 3/9, substructure at 8/9. The weakest component sits in poor condition. 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. Its NBI inventory load rating is 8.7 metric tons.

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

How ALGONQUIN RD compares

▼ 25.9
Load rating vs Illinois average (34.6 t)
Bottom 1%
Lower load rating than 99% of Illinois bridges
229
Bridges in McHenry · 46 in Poor condition
ALGONQUIN RD 8.7 t
Illinois average 34.6 t

Live comparison across Illinois.

Historical Sufficiency Rating

PlainBridge-computed
32.7 / 100 - historical 20–49.9 band
Structural adequacy /55
0.0
Serviceability /30
19.0
Essentiality /15
13.7
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 How the historical reference is calculated.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
3/9
Poor (1–4)
Superstructure
3/9
Poor (1–4)
Substructure
8/9
Good (7–9)
Inventory Load Rating
8.7 t
NBI inventory level (metric tons)
Overall Condition
Poor

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

Structural Details

Year Built
1986
Material
Prestressed Concrete
Number of Spans
1
Structure Length
16.2 m (53 ft)
Deck Width
9.8 m (32 ft)
Owner
Town/Township Highway Agency
Avg Daily Traffic
3,200 vehicles/day
Structure Number
056314800000000

Condition Analysis

  • The deck (driving surface) is in poor condition (3/9), showing advanced deterioration that may require priority repair.
  • At 3/9, the superstructure (beams and supports above the deck) is in poor shape, with advanced wear flagged for priority repair.
  • At 8/9, the substructure (piers and abutments) is in good shape and shows no significant wear.

How to read this record

ALGONQUIN RD 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 ALGONQUIN RD against other structures in McHenry and across Illinois. Illinois 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 ALGONQUIN RD?

ALGONQUIN RD in McHenry, Illinois has a deck rating of 3/9, superstructure rating of 3/9, and substructure rating of 8/9 on the FHWA's 0–9 scale.

How often is ALGONQUIN RD inspected?

ALGONQUIN RD'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 3,200 vehicles per day.

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

FHWA retired that reported status beginning with the 2018 archive. ALGONQUIN RD 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 ALGONQUIN RD?

ALGONQUIN RD has an NBI inventory load rating of 8.7 metric tons.

Who is responsible for maintaining ALGONQUIN RD?

ALGONQUIN RD is owned and maintained by Town/Township Highway Agency.

How old is ALGONQUIN RD and does age affect safety?

ALGONQUIN RD was built in 1986, making it 40 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.