ST117 MAIN ST
Carrying ST117 MAIN ST over I 95 /ST128
0.5 MI NLY RT 20, Middlesex, Massachusetts
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: ST117 MAIN ST
The ST117 MAIN ST bridge in Middlesex, Massachusetts carries ST117 MAIN ST over I 95 /ST128. It was built in 1962, making it 64 years old today. The structure is built primarily of steel continuous and spans 4 sections, stretching 66.4 meters (218 feet) end to end. Daily traffic averages 18,600 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 5/9, substructure at 4/9. 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 28.8 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How ST117 MAIN 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 How the historical reference is calculated.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
- 1962
- Material
- Steel Continuous
- Number of Spans
- 4
- Structure Length
- 66.4 m (218 ft)
- Deck Width
- 18.5 m (61 ft)
- Owner
- State Highway Agency
- Avg Daily Traffic
- 18,600 vehicles/day
- Structure Number
- W040282K3DOTNBI
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) is in fair condition (5/9), with minor deterioration that may require routine maintenance.
- • The substructure (piers and abutments) is in poor condition (4/9), showing advanced deterioration that may require priority repair.
How to read this record
ST117 MAIN 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 ST117 MAIN 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 ST117 MAIN ST?
ST117 MAIN ST in Middlesex, Massachusetts has a deck rating of 4/9, superstructure rating of 5/9, and substructure rating of 4/9 on the FHWA's 0–9 scale.
How often is ST117 MAIN ST inspected?
ST117 MAIN 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 18,600 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. ST117 MAIN 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 ST117 MAIN ST?
ST117 MAIN ST has an NBI inventory load rating of 28.8 metric tons.
Who is responsible for maintaining ST117 MAIN ST?
ST117 MAIN ST is owned and maintained by State Highway Agency.
How old is ST117 MAIN ST and does age affect safety?
ST117 MAIN ST was built in 1962, making it 64 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.