FHWA NBI 2024 Inspection record Public-domain dataset

I 495 SB

Carrying I 495 SB over ST 38 MAIN ST

RT 495 AT RT 38, Middlesex, Massachusetts

Data updated May 2026

FHWA NBI record, refreshed with each annual release.

Poor
30 t Inventory load rating

Bridge Snapshot: I 495 SB

The I 495 SB bridge in Middlesex, Massachusetts carries I 495 SB over ST 38 MAIN ST. It was built in 1961, making it 65 years old today. The structure is built primarily of steel and spans 3 sections, stretching 42.1 meters (138 feet) end to end. Daily traffic averages 63,530 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 5/9, superstructure at 6/9, 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. Its NBI inventory load rating is 29.7 metric tons.

Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.

How I 495 SB compares

▼ 11.5
Load rating vs Massachusetts average (41.2 t)
Bottom 21%
Lower load rating than 79% of Massachusetts bridges
820
Bridges in Middlesex · 72 in Poor condition
I 495 SB 29.7 t
Massachusetts average 41.2 t

Live comparison across Massachusetts.

Historical Sufficiency Rating

PlainBridge-computed
32.6 / 100 - historical 20–49.9 band
Structural adequacy /55
13.6
Serviceability /30
19.0
Essentiality /15
0.0
Special reductions
0

FHWA discontinued this calculated item; it does not determine current condition, funding eligibility, posting, or closure. How the historical reference is calculated.

Condition Ratings

Deck
5/9
Fair (5–6)
Superstructure
6/9
Fair (5–6)
Substructure
3/9
Poor (1–4)
Inventory Load Rating
29.7 t
NBI inventory level (metric tons)
Overall Condition
Poor

Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.

Structural Details

Year Built
1961
Material
Steel
Number of Spans
3
Structure Length
42.1 m (138 ft)
Deck Width
17.4 m (57 ft)
Owner
State Highway Agency
Avg Daily Traffic
63,530 vehicles/day
Structure Number
T030152JTDOTNBI

Condition Analysis

  • The deck (driving surface) is in fair condition (5/9), with minor deterioration that may require routine maintenance.
  • At 6/9, the superstructure (beams and supports above the deck) shows fair condition, with minor wear flagged for upkeep.
  • At 3/9, the substructure (piers and abutments) is in poor shape, with advanced wear flagged for priority repair.

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 5/9, superstructure rating of 6/9, and substructure rating of 3/9 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 63,530 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 29.7 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 1961, making it 65 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.

Data sourced from the Federal Highway Administration National Bridge Inventory. See our methodology for details. Retrieved and formatted by PlainBridges

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.