ST 3 A/BOSTON RD
Carrying ST 3 A/BOSTON RD over WATER CONCORD RIVER
1 MI N OF BILLERICA CTR, Middlesex, Massachusetts
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: ST 3 A/BOSTON RD
The ST 3 A/BOSTON RD bridge in Middlesex, Massachusetts carries ST 3 A/BOSTON RD over WATER CONCORD RIVER. It was built in 1920, making it 106 years old today. The structure is built primarily of concrete and spans 3 sections, stretching 54.9 meters (180 feet) end to end. Daily traffic averages 19,655 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 superstructure at 7/9, substructure at 6/9. The weakest component sits in fair condition. All reported major components score above the Poor range. Its NBI inventory load rating is 56.8 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How ST 3 A/BOSTON RD 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 How the historical reference is calculated.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
- 1920
- Material
- Concrete
- Number of Spans
- 3
- Structure Length
- 54.9 m (180 ft)
- Deck Width
- 12.1 m (40 ft)
- Owner
- State Highway Agency
- Avg Daily Traffic
- 19,655 vehicles/day
- Structure Number
- B120032DGDOTNBI
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗Condition Analysis
- • At 7/9, the superstructure (beams and supports above the deck) is in good shape and shows no significant wear.
- • At 6/9, the substructure (piers and abutments) shows fair condition, with minor wear flagged for upkeep.
How to read this record
This page shows what the last federal inspection recorded, not whether ST 3 A/BOSTON RD 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 3 A/BOSTON RD 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 3 A/BOSTON RD?
ST 3 A/BOSTON RD in Middlesex, Massachusetts, superstructure rating of 7/9, and substructure rating of 6/9 on the FHWA's 0–9 scale.
How often is ST 3 A/BOSTON RD inspected?
ST 3 A/BOSTON RD'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 19,655 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. ST 3 A/BOSTON RD 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 3 A/BOSTON RD?
ST 3 A/BOSTON RD has an NBI inventory load rating of 56.8 metric tons.
Who is responsible for maintaining ST 3 A/BOSTON RD?
ST 3 A/BOSTON RD is owned and maintained by State Highway Agency.
How old is ST 3 A/BOSTON RD and does age affect safety?
ST 3 A/BOSTON RD was built in 1920, making it 106 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.