US 34 (FAP 591)
Carrying US 34 (FAP 591) over SOMONAUK CREEK
1.1 MI. W. SANDWICH, DeKalb, Illinois
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: US 34 (FAP 591)
The US 34 (FAP 591) bridge in DeKalb, Illinois carries US 34 (FAP 591) over SOMONAUK CREEK. It was built in 1991, making it 35 years old today. The structure is built primarily of prestressed concrete and spans 3 sections, stretching 38.6 meters (127 feet) end to end. Daily traffic averages 4,700 vehicles, placing it in the moderately-trafficked tier of Illinois bridges. It is owned and maintained by State Highway Agency.
The latest FHWA inspection records show a deck rating of 7/9, superstructure at 8/9, substructure at 8/9. The weakest component sits in good condition. All reported major components score above the Poor range. Its NBI inventory load rating is 52.2 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How US 34 (FAP 591) compares
Live comparison across Illinois.
Historical Sufficiency Rating
PlainBridge-computedFHWA discontinued this calculated item; it does not determine current condition, funding eligibility, posting, or closure. How the historical reference is calculated.
Condition Ratings
Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.
Structural Details
- Year Built
- 1991
- Material
- Prestressed Concrete
- Number of Spans
- 3
- Structure Length
- 38.6 m (127 ft)
- Deck Width
- 13.2 m (43 ft)
- Owner
- State Highway Agency
- Avg Daily Traffic
- 4,700 vehicles/day
- Structure Number
- 019003900000000
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗Condition Analysis
- • At 7/9, the deck (driving surface) is in good shape and shows no significant wear.
- • The superstructure (beams and supports above the deck) rates good at 8/9, with no significant deterioration on file.
- • At 8/9, 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 US 34 (FAP 591) 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 US 34 (FAP 591) against other structures in DeKalb 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 US 34 (FAP 591)?
US 34 (FAP 591) in DeKalb, Illinois has a deck rating of 7/9, superstructure rating of 8/9, and substructure rating of 8/9 on the FHWA's 0–9 scale.
How often is US 34 (FAP 591) inspected?
US 34 (FAP 591)'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 4,700 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. US 34 (FAP 591) 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 US 34 (FAP 591)?
US 34 (FAP 591) has an NBI inventory load rating of 52.2 metric tons.
Who is responsible for maintaining US 34 (FAP 591)?
US 34 (FAP 591) is owned and maintained by State Highway Agency.
How old is US 34 (FAP 591) and does age affect safety?
US 34 (FAP 591) was built in 1991, making it 35 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.
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.