31ST STREET
Carrying 31ST STREET over METRA ELEC & CN
3100 S & 628 E, Cook, Illinois
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
31ST STREET in Cook, Illinois sits above 7% of rated Illinois bridges on inventory load rating (21 t), while its 1921 build year is earlier than 96% of Cook's recorded-year cohort (1,721 bridges).
31ST STREET in Cook, Illinois is rated Poor in the FHWA's 2024 National Bridge Inventory. Built in 1921, it carries 3 rated components on the inspecting agency's 0-9 scale, and its weakest reported component scores 3. 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 IL:016617300000000
PRE-1950 · STEEL · LONG-SPAN-RUN · SUB-LED · ARTERIAL-ADT · STANDARD-LOAD · CAT-POOR
- PRE-1950 Pre-1950
- STEEL Steel
- LONG-SPAN-RUN 4 spans
- SUB-LED Substructure-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.
Bridge Snapshot: 31ST STREET
The 31ST STREET bridge in Cook, Illinois carries 31ST STREET over METRA ELEC & CN. It was built in 1921, making it 105 years old today. It was last reconstructed in 1967, extending its service life. The structure is built primarily of steel continuous and spans 4 sections, stretching 85.5 meters (281 feet) end to end. Daily traffic averages 7,550 vehicles, placing it in the moderately-trafficked tier of Illinois bridges. It is owned and maintained by City/Municipal Highway Agency.
The latest FHWA inspection records show a deck rating of 5/9, superstructure at 5/9, substructure at 3/9. The weakest component sits in poor condition. At least one major component here scores 4 or below, which produces a Poor condition classification under FHWA's current reporting rules.
How 31ST STREET compares
Age against the county: built in 1921, earlier than 1,656 of Cook's 1,721 bridges with a recorded construction year (96%), 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.
Live comparison across Illinois bridges with a recorded inventory load rating (26,904 of 26,928 rated).
31ST STREET vs every rated Illinois bridge
Inventory load rating (metric tons), FHWA NBI, this state
21 Top 93% higher than 7% of 26,904 bridges
rated Illinois 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
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.
Cook inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 1,721 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
- 1921
- Last Reconstructed
- 1967
- Material
- Steel Continuous
- Number of Spans
- 4
- Structure Length
- 85.5 m (281 ft)
- Deck Width
- 24.4 m (80 ft)
- Owner
- City/Municipal Highway Agency
- Avg Daily Traffic
- 7,550 vehicles/day
- Structure Number
- 016617300000000
Condition Analysis
- • At 5/9, the deck (driving surface) shows fair condition, with minor wear flagged for upkeep.
- • At 5/9, the superstructure (beams and supports above the deck) shows fair condition, with minor wear flagged for upkeep.
- • The substructure (piers and abutments) rates poor at 3/9, with advanced deterioration recorded on the latest inspection.
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗How to read this record
31ST 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 31ST STREET against other structures in Cook 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 31ST STREET?
31ST STREET in Cook, Illinois has a deck rating of 5/9, superstructure rating of 5/9, and substructure rating of 3/9 on the FHWA's 0–9 scale.
How often is 31ST STREET inspected?
31ST 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 7,550 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. 31ST 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 31ST STREET?
31ST STREET has an NBI inventory load rating of 21.4 metric tons.
Who is responsible for maintaining 31ST STREET?
31ST STREET is owned and maintained by City/Municipal Highway Agency.
How old is 31ST STREET and does age affect safety?
31ST STREET was built in 1921, making it 105 years old and last reconstructed in 1967.
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.
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.