RTE 420
Carrying RTE 420 over SQUEAK BROOK
3.3 MI NW JCT RTS 420 +11, St. Lawrence, New York
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
RTE 420 in St. Lawrence, New York sits above 68% of rated New York bridges on inventory load rating (47 t), while its 1944 build year is earlier than 82% of St. Lawrence's recorded-year cohort (312 bridges).
RTE 420 in St. Lawrence, New York is rated Fair in the FHWA's 2024 National Bridge Inventory. Built in 1944, it carries 1 rated component on the inspecting agency's 0-9 scale, and its weakest reported component scores 6. The lowest applicable rating sets the federal condition category, so this Fair 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 NY:000000001048250
PRE-1950 · CONCRETE · SINGLE-SPAN · CULVERT-LED · ARTERIAL-ADT · HEAVY-LOAD · CAT-FAIR
- PRE-1950 Pre-1950
- CONCRETE Concrete
- SINGLE-SPAN Single span
- CULVERT-LED Culvert-led
- ARTERIAL-ADT Arterial ADT
- HEAVY-LOAD Heavy load
- CAT-FAIR Fair
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: RTE 420
The RTE 420 bridge in St. Lawrence, New York carries RTE 420 over SQUEAK BROOK. It was built in 1944, making it 82 years old today. The structure is built primarily of concrete and spans 1 section, stretching 7.3 meters (24 feet) end to end. Daily traffic averages 2,820 vehicles, placing it in the moderately-trafficked tier of New York bridges. It is owned and maintained by State Highway Agency.
The latest FHWA inspection records show culvert at 6/9. The weakest component sits in fair condition. All reported major components score above the Poor range.
How RTE 420 compares
Age against the county: built in 1944, earlier than 257 of St. Lawrence's 312 bridges with a recorded construction year (82%), against a county median build year of 1980. Age is not a defect on its own, but it is the population from which future Poor ratings are drawn.
Live comparison across New York bridges with a recorded inventory load rating (17,641 of 17,642 rated).
RTE 420 vs every rated New York bridge
Inventory load rating (metric tons), FHWA NBI, this state
47 Top 32% higher than 68% of 17,641 bridges
rated New York 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.
St. Lawrence inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 312 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
- 1944
- Material
- Concrete
- Number of Spans
- 1
- Structure Length
- 7.3 m (24 ft) 0
- Owner
- State Highway Agency
- Avg Daily Traffic
- 2,820 vehicles/day
- Structure Number
- 000000001048250
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗How to read this record
This page shows what the last federal inspection recorded, not whether RTE 420 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 RTE 420 against other structures in St. Lawrence and across New York. New York 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 RTE 420?
RTE 420 in St. Lawrence, New York on the FHWA's 0–9 scale.
How often is RTE 420 inspected?
RTE 420'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 2,820 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. RTE 420 is currently shown as Fair condition from its component ratings; that category is not a live closure or safety decision.
What is the inventory load rating for RTE 420?
RTE 420 has an NBI inventory load rating of 47.2 metric tons.
Who is responsible for maintaining RTE 420?
RTE 420 is owned and maintained by State Highway Agency.
How old is RTE 420 and does age affect safety?
RTE 420 was built in 1944, making it 82 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.
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.