I 495 SB
Carrying I 495 SB over WATER ASSABET RIVER
0.25 MI NW RT 290, Middlesex, Massachusetts
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: I 495 SB
The I 495 SB bridge in Middlesex, Massachusetts carries I 495 SB over WATER ASSABET RIVER. It was built in 1963, making it 63 years old today. The structure is built primarily of steel and spans 1 section, stretching 25.3 meters (83 feet) end to end. Daily traffic averages 56,081 vehicles, placing it in the heavily-trafficked tier of Massachusetts bridges. It is owned and maintained by State Highway Agency.
The latest FHWA inspection records show a deck rating of 4/9, superstructure at 7/9, substructure at 6/9. The weakest component sits in poor condition. A component scored 4 or below, placing this bridge in the federal Poor condition category rather than declaring it unsafe or closed. Its NBI inventory load rating is 31.3 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How I 495 SB compares
Live comparison across Massachusetts.
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 How the historical reference is calculated.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
- 1963
- Material
- Steel
- Number of Spans
- 1
- Structure Length
- 25.3 m (83 ft)
- Deck Width
- 17.1 m (56 ft)
- Owner
- State Highway Agency
- Avg Daily Traffic
- 56,081 vehicles/day
- Structure Number
- H2501627GDOTNBI
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗Condition Analysis
- • The deck (driving surface) is in poor condition (4/9), showing advanced deterioration that may require priority repair.
- • The superstructure (beams and supports above the deck) rates good at 7/9, with no significant deterioration on file.
- • At 6/9, the substructure (piers and abutments) shows fair condition, with minor wear flagged for upkeep.
How to read this record
I 495 SB 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 I 495 SB against other structures in Middlesex and across Massachusetts. Massachusetts 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 I 495 SB?
I 495 SB in Middlesex, Massachusetts has a deck rating of 4/9, superstructure rating of 7/9, and substructure rating of 6/9 on the FHWA's 0–9 scale.
How often is I 495 SB inspected?
I 495 SB'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 56,081 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. I 495 SB 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 I 495 SB?
I 495 SB has an NBI inventory load rating of 31.3 metric tons.
Who is responsible for maintaining I 495 SB?
I 495 SB is owned and maintained by State Highway Agency.
How old is I 495 SB and does age affect safety?
I 495 SB was built in 1963, making it 63 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.