ST 9 BOYLSTON ST
Carrying ST 9 BOYLSTON ST over TR GREEN LINE D
2.3 KM 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 TR GREEN LINE D. It was built in 1905, making it 121 years old today. It was last reconstructed in 1960, extending its service life. The structure is built primarily of steel and spans 1 section, stretching 17.1 meters (56 feet) end to end. Daily traffic averages 96,206 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 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 28.3 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 How the historical reference is calculated.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
- 1905
- Last Reconstructed
- 1960
- Material
- Steel
- Number of Spans
- 1
- Structure Length
- 17.1 m (56 ft)
- Deck Width
- 27.4 m (90 ft)
- Owner
- State Highway Agency
- Avg Daily Traffic
- 96,206 vehicles/day
- Structure Number
- N120402EEDOTNBI
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗Condition Analysis
- • The deck (driving surface) rates fair at 5/9, minor deterioration that routine maintenance should address.
- • The superstructure (beams and supports above the deck) is in poor condition (4/9), showing advanced deterioration that may require priority repair.
- • At 5/9, the substructure (piers and abutments) shows fair condition, with minor wear flagged for upkeep.
How to read this record
ST 9 BOYLSTON ST 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 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 4/9, and substructure rating of 5/9 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 96,206 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 Poor 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 28.3 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 1905, making it 121 years old and last reconstructed in 1960.
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.