HWY MERRIMACK ST
Carrying HWY MERRIMACK ST over WATER MERRIMACK CANAL
AT DUTTON ST, Middlesex, Massachusetts
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: HWY MERRIMACK ST
The HWY MERRIMACK ST bridge in Middlesex, Massachusetts carries HWY MERRIMACK ST over WATER MERRIMACK CANAL. It was built in 1823, making it 203 years old today. It was last reconstructed in 1890, extending its service life. The structure is built primarily of masonry and spans 1 section, stretching 11.0 meters (36 feet) end to end. Daily traffic averages 20,520 vehicles, placing it in the heavily-trafficked tier of Massachusetts bridges. It is owned and maintained by City/Municipal Highway Agency.
The latest FHWA inspection records show superstructure at 6/9, substructure at 7/9. The weakest component sits in fair condition. All reported major components score above the Poor range. Its NBI inventory load rating is 29.2 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How HWY MERRIMACK 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 How the historical reference is calculated.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
- 1823
- Last Reconstructed
- 1890
- Material
- Masonry
- Number of Spans
- 1
- Structure Length
- 11.0 m (36 ft)
- Deck Width
- 22.3 m (73 ft)
- Owner
- City/Municipal Highway Agency
- Avg Daily Traffic
- 20,520 vehicles/day
- Structure Number
- L1504687MMUNNBI
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗Condition Analysis
- • The superstructure (beams and supports above the deck) is in fair condition (6/9), with minor deterioration that may require routine maintenance.
- • The substructure (piers and abutments) rates good at 7/9, with no significant deterioration on file.
How to read this record
This page shows what the last federal inspection recorded, not whether HWY MERRIMACK ST 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 HWY MERRIMACK 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 HWY MERRIMACK ST?
HWY MERRIMACK ST in Middlesex, Massachusetts, superstructure rating of 6/9, and substructure rating of 7/9 on the FHWA's 0–9 scale.
How often is HWY MERRIMACK ST inspected?
HWY MERRIMACK 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 20,520 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. HWY MERRIMACK ST 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 HWY MERRIMACK ST?
HWY MERRIMACK ST has an NBI inventory load rating of 29.2 metric tons.
Who is responsible for maintaining HWY MERRIMACK ST?
HWY MERRIMACK ST is owned and maintained by City/Municipal Highway Agency.
How old is HWY MERRIMACK ST and does age affect safety?
HWY MERRIMACK ST was built in 1823, making it 203 years old and last reconstructed in 1890.
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.