GRANTVILLE ROAD
Carrying GRANTVILLE ROAD over MAD RIVER
500 S OF DANBURY QUARTER, Unknown County, Connecticut
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
GRANTVILLE ROAD in Unknown County, Connecticut sits above 15% of rated Connecticut bridges on inventory load rating (31 t), while its 1956 build year is earlier than 67% of Unknown County's recorded-year cohort (471 bridges).
GRANTVILLE ROAD in Unknown County, Connecticut is rated Poor in the FHWA's 2024 National Bridge Inventory. Built in 1956, it carries 3 rated components on the inspecting agency's 0-9 scale, and its weakest reported component scores 4. 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 CT:05132
INTERSTATE-ERA · PRESTRESS · SINGLE-SPAN · TIED-CTRL · LOCAL-ADT · STANDARD-LOAD · CAT-POOR
- INTERSTATE-ERA 1950–1979
- PRESTRESS Prestressed concrete
- SINGLE-SPAN Single span
- TIED-CTRL Tied control
- LOCAL-ADT Local 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.
Structural health score
A composite of the deck, superstructure, and substructure NBI condition ratings plus the inventory load rating, benchmarked against the full national bridge corpus, distinct from the Good/Fair/Poor category above.
Bridge Snapshot: GRANTVILLE ROAD
The GRANTVILLE ROAD bridge in Unknown County, Connecticut carries GRANTVILLE ROAD over MAD RIVER. It was built in 1956, making it 70 years old today. The structure is built primarily of prestressed concrete and spans 1 section, stretching 10.4 meters (34 feet) end to end. Daily traffic averages 133 vehicles, placing it in the lower-traffic tier of Connecticut bridges. It is owned and maintained by Town/Township Highway Agency.
The latest FHWA inspection places the weakest component in poor condition (see the full component ratings below). At least one major component here scores 4 or below, which produces a Poor condition classification under FHWA's current reporting rules.
How GRANTVILLE ROAD compares
Age against the county: built in 1956, earlier than 314 of Unknown County's 471 bridges with a recorded construction year (67%), against a county median build year of 1964. Age is not a defect on its own, but it is the population from which future Poor ratings are drawn.
Live comparison across Connecticut bridges with a recorded inventory load rating (4,365 rated).
GRANTVILLE ROAD vs every rated Connecticut bridge
Inventory load rating (metric tons), FHWA NBI, this state
31 Top 85% higher than 15% of 4,365 bridges
rated Connecticut 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.
Unknown County inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 471 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
- 1956
- Material
- Prestressed Concrete
- Number of Spans
- 1
- Structure Length
- 10.4 m (34 ft)
- Deck Width
- 8.3 m (27 ft)
- Owner
- Town/Township Highway Agency
- Avg Daily Traffic
- 133 vehicles/day
- Structure Number
- 05132
Condition Analysis
- • The deck (driving surface) is in poor condition (4/9), showing advanced deterioration on the inspecting agency's 0-9 scale.
- • The superstructure (beams and supports above the deck) is in poor condition (4/9), showing advanced deterioration on the inspecting agency's 0-9 scale.
- • The substructure (piers and abutments) rates good at 7/9, with no significant deterioration on file.
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗How to read this record
GRANTVILLE ROAD 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 GRANTVILLE ROAD against other structures in Unknown County and across Connecticut. Connecticut 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 GRANTVILLE ROAD?
GRANTVILLE ROAD in Unknown County, Connecticut has a deck rating of 4/9, superstructure rating of 4/9, and substructure rating of 7/9 on the FHWA's 0–9 scale.
How often is GRANTVILLE ROAD inspected?
GRANTVILLE ROAD'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 133 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. GRANTVILLE ROAD 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 GRANTVILLE ROAD?
GRANTVILLE ROAD has an NBI inventory load rating of 30.8 metric tons.
Who is responsible for maintaining GRANTVILLE ROAD?
GRANTVILLE ROAD is owned and maintained by Town/Township Highway Agency.
How old is GRANTVILLE ROAD and does age affect safety?
GRANTVILLE ROAD was built in 1956, making it 70 years old.
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.