ST129 LOWELL ST
Carrying ST129 LOWELL ST over I 93
RT 129 AT RT 93, Middlesex, Massachusetts
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
ST129 LOWELL ST in Middlesex, Massachusetts sits above 16% of rated Massachusetts bridges on inventory load rating (27 t), while its 1957 build year is earlier than 58% of Middlesex's recorded-year cohort (818 bridges).
ST129 LOWELL ST in Middlesex, Massachusetts is rated Poor in the FHWA's 2024 National Bridge Inventory. Built in 1957, it carries 3 rated components on the inspecting agency's 0-9 scale, and its weakest reported component scores 3. The lowest applicable rating sets the federal condition category, so this Poor result describes the weakest reported component rather than the structure as a whole. No NBI category is a closure decision or a live crossing-safety verdict.
NBI record plate
Structure MA:W380292KVDOTNBI
INTERSTATE-ERA · STEEL · MULTI-SPAN · SUB-LED · HEAVY-ADT · STANDARD-LOAD · CAT-POOR
- INTERSTATE-ERA 1950–1979
- STEEL Steel
- MULTI-SPAN 2 spans
- SUB-LED Substructure-led
- HEAVY-ADT Heavy ADT
- STANDARD-LOAD Standard load
- CAT-POOR Poor
Inspection-sheet codes from this record’s year, material family, spans, controlling component, ADT, inventory load, and NBI category, not a live closure verdict.
Bridge Snapshot: ST129 LOWELL ST
The ST129 LOWELL ST bridge in Middlesex, Massachusetts carries ST129 LOWELL ST over I 93. It was built in 1957, making it 69 years old today. The structure is built primarily of steel and spans 2 sections, stretching 79.2 meters (260 feet) end to end. Daily traffic averages 25,500 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 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.
How ST129 LOWELL ST compares
Age against the county: built in 1957, earlier than 477 of Middlesex's 818 bridges with a recorded construction year (58%), against a county median build year of 1960. Age is not a defect on its own, but it is the population from which future Poor ratings are drawn.
Live comparison across Massachusetts bridges with a recorded inventory load rating (5,295 rated).
ST129 LOWELL ST vs every rated Massachusetts bridge
Inventory load rating (metric tons), FHWA NBI, this state
27 Top 84% higher than 16% of 5,295 bridges
rated Massachusetts bridges, bucketed by value
Each bar is a band; taller bars hold more bridges. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source FHWA National Bridge Inventory · August 2026
Condition Ratings
Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.
Reported 0–9 component ratings from the FHWA NBI. The highlighted component is the lowest reported input to this record’s current condition category; it is not a closure or live crossing-safety decision.
Middlesex inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 818 bridges in this county. Orthogonal to this structure's component profile above: a county catalog share, not a live crossing-safety verdict.
Structural Details
- Year Built
- 1957
- Material
- Steel
- Number of Spans
- 2
- Structure Length
- 79.2 m (260 ft)
- Deck Width
- 16.4 m (54 ft)
- Owner
- State Highway Agency
- Avg Daily Traffic
- 25,500 vehicles/day
- Structure Number
- W380292KVDOTNBI
Condition Analysis
- • At 4/9, the deck (driving surface) is in poor shape, with advanced wear on file for this vintage.
- • 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 (3/9), showing advanced deterioration on the inspecting agency's 0-9 scale.
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗How to read this record
ST129 LOWELL 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 ST129 LOWELL 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 ST129 LOWELL ST?
ST129 LOWELL ST in Middlesex, Massachusetts has a deck rating of 4/9, superstructure rating of 5/9, and substructure rating of 3/9 on the FHWA's 0–9 scale.
How often is ST129 LOWELL ST inspected?
ST129 LOWELL 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 25,500 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. ST129 LOWELL 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 ST129 LOWELL ST?
ST129 LOWELL ST has an NBI inventory load rating of 26.8 metric tons.
Who is responsible for maintaining ST129 LOWELL ST?
ST129 LOWELL ST is owned and maintained by State Highway Agency.
How old is ST129 LOWELL ST and does age affect safety?
ST129 LOWELL ST was built in 1957, making it 69 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.
Share this inspection record
Send this source-bounded record or download its data card. An NBI condition category is not a closure or live crossing-safety verdict.
Every figure on PlainBridges is rendered directly from federal source data, no number is typed in by an editor. Component ratings, ADT, and condition category on this page are copied from the NBI record for this structure; no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2024 NBI release. NBI condition categories reflect the latest reported inventory record, not a live safety, closure, or travel decision.