I 93 NB OFFRAMP
Carrying I 93 NB OFFRAMP over ST 38 NB/MYSTIC AVE
3.2 KM N OF JCT I93&US1, Middlesex, Massachusetts
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
I 93 NB OFFRAMP in Middlesex, Massachusetts is rated Poor in the FHWA's 2024 National Bridge Inventory.
Built in 1973, it carries 3 rated components on the inspecting agency's 0-9 scale, and its weakest reported component scores 4. 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:S170363BKDOTNBI
INTERSTATE-ERA · STEEL · LONG-SPAN-RUN · SUPER-LED · HEAVY-ADT · STANDARD-LOAD · CAT-POOR
- INTERSTATE-ERA 1950–1979
- STEEL Steel
- LONG-SPAN-RUN 5 spans
- SUPER-LED Superstructure-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: I 93 NB OFFRAMP
The I 93 NB OFFRAMP bridge in Middlesex, Massachusetts carries I 93 NB OFFRAMP over ST 38 NB/MYSTIC AVE. It was built in 1973, making it 53 years old today. The structure is built primarily of steel and spans 5 sections, stretching 113.4 meters (372 feet) end to end. Daily traffic averages 19,300 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.
How I 93 NB OFFRAMP compares
Age against the county: built in 1973, earlier than 242 of Middlesex's 818 bridges with a recorded construction year (30%), against a county median build year of 1960. This is one of the newer structures in its county.
Live comparison across Massachusetts bridges with a recorded inventory load rating (5,295 rated).
I 93 NB OFFRAMP vs every rated Massachusetts bridge
Inventory load rating (metric tons), FHWA NBI, this state
32 Top 73% higher than 27% 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
- 1973
- Material
- Steel
- Number of Spans
- 5
- Structure Length
- 113.4 m (372 ft)
- Deck Width
- 11.7 m (38 ft)
- Owner
- State Highway Agency
- Avg Daily Traffic
- 19,300 vehicles/day
- Structure Number
- S170363BKDOTNBI
Condition Analysis
- • The deck (driving surface) is in fair condition (5/9), with minor deterioration that may require routine maintenance.
- • The superstructure (beams and supports above the deck) rates poor at 4/9, with advanced deterioration recorded on the latest inspection.
- • The substructure (piers and abutments) rates fair at 5/9, minor deterioration that routine maintenance should address.
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗How to read this record
I 93 NB OFFRAMP 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 I 93 NB OFFRAMP 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 I 93 NB OFFRAMP?
I 93 NB OFFRAMP 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 I 93 NB OFFRAMP inspected?
I 93 NB OFFRAMP'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 19,300 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. I 93 NB OFFRAMP 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 I 93 NB OFFRAMP?
I 93 NB OFFRAMP has an NBI inventory load rating of 31.6 metric tons.
Who is responsible for maintaining I 93 NB OFFRAMP?
I 93 NB OFFRAMP is owned and maintained by State Highway Agency.
How old is I 93 NB OFFRAMP and does age affect safety?
I 93 NB OFFRAMP was built in 1973, making it 53 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.