ST 9 BOYLSTON ST
Carrying ST 9 BOYLSTON ST over HWY CENTRE ST
1.5 MI ELY RT 128, Middlesex, Massachusetts
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: ST 9 BOYLSTON ST
The ST 9 BOYLSTON ST bridge in Middlesex, Massachusetts carries ST 9 BOYLSTON ST over HWY CENTRE ST. It was built in 1932, making it 94 years old today. The structure is built primarily of steel and spans 1 section, stretching 29.0 meters (95 feet) end to end. Daily traffic averages 73,966 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 5/9, substructure at 6/9. The weakest component sits in fair condition. None of this bridge's reported major components fall into the Poor condition range. Its NBI inventory load rating is 22.5 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How ST 9 BOYLSTON ST 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 How the historical reference is calculated.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
- 1932
- Material
- Steel
- Number of Spans
- 1
- Structure Length
- 29.0 m (95 ft)
- Deck Width
- 18.9 m (62 ft)
- Owner
- State Highway Agency
- Avg Daily Traffic
- 73,966 vehicles/day
- Structure Number
- N120512EDDOTNBI
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 5/9, the superstructure (beams and supports above the deck) shows fair condition, with minor wear flagged for upkeep.
- • The substructure (piers and abutments) is in fair condition (6/9), with minor deterioration that may require routine maintenance.
How to read this record
This page shows what the last federal inspection recorded, not whether ST 9 BOYLSTON ST 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 ST 9 BOYLSTON ST 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 ST 9 BOYLSTON ST?
ST 9 BOYLSTON ST in Middlesex, Massachusetts has a deck rating of 5/9, superstructure rating of 5/9, and substructure rating of 6/9 on the FHWA's 0–9 scale.
How often is ST 9 BOYLSTON ST inspected?
ST 9 BOYLSTON ST'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 73,966 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. ST 9 BOYLSTON ST 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 ST 9 BOYLSTON ST?
ST 9 BOYLSTON ST has an NBI inventory load rating of 22.5 metric tons.
Who is responsible for maintaining ST 9 BOYLSTON ST?
ST 9 BOYLSTON ST is owned and maintained by State Highway Agency.
How old is ST 9 BOYLSTON ST and does age affect safety?
ST 9 BOYLSTON ST was built in 1932, making it 94 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.