RTE 51
Carrying RTE 51 over UNADILLA RIVER
01MI S JCT RTS 51+20, Herkimer, New York
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: RTE 51
The RTE 51 bridge in Herkimer, New York carries RTE 51 over UNADILLA RIVER. It was built in 1937, making it 89 years old today. The structure is built primarily of steel and spans 1 section, stretching 15.8 meters (52 feet) end to end. Daily traffic averages 1,531 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 a deck rating of 5/9, superstructure at 4/9, substructure at 5/9. 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 31.8 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How RTE 51 compares
Live comparison across New York.
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 How the historical reference is calculated.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
- 1937
- Material
- Steel
- Number of Spans
- 1
- Structure Length
- 15.8 m (52 ft)
- Deck Width
- 12.9 m (42 ft)
- Owner
- State Highway Agency
- Avg Daily Traffic
- 1,531 vehicles/day
- Structure Number
- 000000001026470
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗Condition Analysis
- • At 5/9, the deck (driving surface) shows fair condition, with minor wear flagged for upkeep.
- • At 4/9, the superstructure (beams and supports above the deck) is in poor shape, with advanced wear flagged for priority repair.
- • The substructure (piers and abutments) is in fair condition (5/9), with minor deterioration that may require routine maintenance.
How to read this record
RTE 51 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 RTE 51 against other structures in Herkimer 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 51?
RTE 51 in Herkimer, New York has a deck rating of 5/9, superstructure rating of 4/9, and substructure rating of 5/9 on the FHWA's 0–9 scale.
How often is RTE 51 inspected?
RTE 51'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 1,531 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. RTE 51 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 RTE 51?
RTE 51 has an NBI inventory load rating of 31.8 metric tons.
Who is responsible for maintaining RTE 51?
RTE 51 is owned and maintained by State Highway Agency.
How old is RTE 51 and does age affect safety?
RTE 51 was built in 1937, making it 89 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.